diff --git a/src/coreclr/debug/daccess/request.cpp b/src/coreclr/debug/daccess/request.cpp
index 74974c3b6f48e..65080489ad5e4 100644
--- a/src/coreclr/debug/daccess/request.cpp
+++ b/src/coreclr/debug/daccess/request.cpp
@@ -1334,7 +1334,7 @@ ClrDataAccess::GetMethodDescName(CLRDATA_ADDRESS methodDesc, unsigned int count,
                     nChars > 0 && nChars <= ARRAY_SIZE(path))
                 {
                     WCHAR* pFile = path + nChars - 1;
-                    while ((pFile >= path) && (*pFile != W('\\')))
+                    while ((pFile >= path) && (*pFile != DIRECTORY_SEPARATOR_CHAR_W))
                     {
                         pFile--;
                     }
diff --git a/src/coreclr/ildasm/dis.cpp b/src/coreclr/ildasm/dis.cpp
index 81ccc1928b8ff..1221b81e8b5c6 100644
--- a/src/coreclr/ildasm/dis.cpp
+++ b/src/coreclr/ildasm/dis.cpp
@@ -1115,8 +1115,10 @@ BOOL Disassemble(IMDInternalImport *pImport, BYTE *ILHeader, void *GUICookie, md
                             pFile = NULL;
                             if(fopen_s(&pFile,szFileName,"rt") != 0)
                             {
-                                char* pch = strrchr(szFileName,'\\');
+                                char* pch = strrchr(szFileName, DIRECTORY_SEPARATOR_CHAR_A);
+#ifdef HOST_WINDOWS
                                 if(pch == NULL) pch = strrchr(szFileName,':');
+#endif
                                 pFile = NULL;
                                 if(pch) fopen_s(&pFile,pch+1,"rt");
                             }
diff --git a/src/coreclr/ildasm/dman.cpp b/src/coreclr/ildasm/dman.cpp
index cee38f4488227..5c100431094c5 100644
--- a/src/coreclr/ildasm/dman.cpp
+++ b/src/coreclr/ildasm/dman.cpp
@@ -782,8 +782,10 @@ void DumpManifestResources(void* GUICookie)
             static WCHAR wzFileName[2048];
 
             WszMultiByteToWideChar(CP_UTF8,0,g_szOutputFile,-1,wzFileName,2048);
-            wzName = wcsrchr(wzFileName,'\\');
+            wzName = wcsrchr(wzFileName,DIRECTORY_SEPARATOR_CHAR_W);
+#ifdef HOST_WINDOWS
             if(wzName == NULL) wzName = wcsrchr(wzFileName,':');
+#endif
             if (wzName == NULL) wzName = wzFileName;
             else wzName++;
 
diff --git a/src/coreclr/inc/longfilepathwrappers.h b/src/coreclr/inc/longfilepathwrappers.h
index 5a77cb102a57a..ee394aa0b7758 100644
--- a/src/coreclr/inc/longfilepathwrappers.h
+++ b/src/coreclr/inc/longfilepathwrappers.h
@@ -5,6 +5,8 @@
 #define _WIN_PATH_APIS_WRAPPER_
 class SString;
 
+#ifdef HOST_WINDOWS
+
 HMODULE
 LoadLibraryExWrapper(
     _In_ LPCWSTR lpLibFileName,
@@ -35,7 +37,6 @@ GetFileAttributesExWrapper(
     _Out_writes_bytes_(sizeof(WIN32_FILE_ATTRIBUTE_DATA)) LPVOID lpFileInformation
     );
 
-#ifndef HOST_UNIX
 BOOL
 CopyFileExWrapper(
     _In_        LPCWSTR lpExistingFileName,
@@ -46,7 +47,7 @@ CopyFileExWrapper(
     _Inout_opt_ LPBOOL pbCancel,
     _In_        DWORD dwCopyFlags
     );
-#endif //HOST_UNIX
+#endif //HOST_WINDOWS
 
 DWORD
 SearchPathWrapper(
diff --git a/src/coreclr/inc/nsutilpriv.h b/src/coreclr/inc/nsutilpriv.h
index 5ea9d0eba2ed6..238b34618b661 100644
--- a/src/coreclr/inc/nsutilpriv.h
+++ b/src/coreclr/inc/nsutilpriv.h
@@ -208,8 +208,6 @@ void MakeNestedTypeName(                // throws on out of memory
 #define ASSEMBLY_SEPARATOR_STR ", "
 #define ASSEMBLY_SEPARATOR_WSTR W(", ")
 #define ASSEMBLY_SEPARATOR_LEN 2
-#define BACKSLASH_CHAR '\\'
-#define BACKSLASH_WCHAR W('\\')
 #define NESTED_SEPARATOR_CHAR '+'
 #define NESTED_SEPARATOR_WCHAR W('+')
 #define NESTED_SEPARATOR_STR "+"
diff --git a/src/coreclr/inc/winwrap.h b/src/coreclr/inc/winwrap.h
index 522ae3150e258..652c0b8065331 100644
--- a/src/coreclr/inc/winwrap.h
+++ b/src/coreclr/inc/winwrap.h
@@ -189,11 +189,17 @@
 
 //File and Directory Functions which need special handling for LongFile Names
 //Note only the functions which are currently used are defined
+#ifdef HOST_WINDOWS
 #define WszLoadLibrary         LoadLibraryExWrapper
 #define WszLoadLibraryEx       LoadLibraryExWrapper
 #define WszCreateFile          CreateFileWrapper
-#define WszGetFileAttributes   GetFileAttributesWrapper
 #define WszGetFileAttributesEx GetFileAttributesExWrapper
+#else // HOST_WINDOWS
+#define WszLoadLibrary         LoadLibraryW
+#define WszLoadLibraryEx       LoadLibraryExW
+#define WszCreateFile          CreateFileW
+#define WszGetFileAttributesEx GetFileAttributesExW
+#endif // HOST_WINDOWS
 
 //Can not use extended syntax
 #define WszGetFullPathName     GetFullPathNameW
diff --git a/src/coreclr/jit/error.cpp b/src/coreclr/jit/error.cpp
index b5af43193faa5..0ca3c39f34448 100644
--- a/src/coreclr/jit/error.cpp
+++ b/src/coreclr/jit/error.cpp
@@ -239,7 +239,7 @@ DWORD getBreakOnBadCode()
 /*****************************************************************************/
 void debugError(const char* msg, const char* file, unsigned line)
 {
-    const char* tail = strrchr(file, '\\');
+    const char* tail = strrchr(file, DIRECTORY_SEPARATOR_CHAR_A);
     if (tail != nullptr)
     {
         tail = tail + 1;
diff --git a/src/coreclr/jit/importer.cpp b/src/coreclr/jit/importer.cpp
index df7834354af19..bcac8ba6b23d8 100644
--- a/src/coreclr/jit/importer.cpp
+++ b/src/coreclr/jit/importer.cpp
@@ -88,7 +88,7 @@ void Compiler::verRaiseVerifyExceptionIfNeeded(INDEBUG(const char* msg) DEBUGARG
                                                    DEBUGARG(unsigned line))
 {
 #ifdef DEBUG
-    const char* tail = strrchr(file, '\\');
+    const char* tail = strrchr(file, DIRECTORY_SEPARATOR_CHAR_A);
     if (tail)
     {
         file = tail + 1;
diff --git a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/InteropServices/NativeLibrary.NativeAot.Unix.cs b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/InteropServices/NativeLibrary.NativeAot.Unix.cs
index 695b904825ea3..91203aff615c5 100644
--- a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/InteropServices/NativeLibrary.NativeAot.Unix.cs
+++ b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/InteropServices/NativeLibrary.NativeAot.Unix.cs
@@ -11,9 +11,6 @@ public static partial class NativeLibrary
 
         private static IntPtr LoadLibraryHelper(string libraryName, int _ /*flags*/, ref LoadLibErrorTracker errorTracker)
         {
-            // do the Dos/Unix conversion
-            libraryName = libraryName.Replace('\\', '/');
-
             IntPtr ret = Interop.Sys.LoadLibrary(libraryName);
             if (ret == IntPtr.Zero)
             {
diff --git a/src/coreclr/pal/inc/mbusafecrt.h b/src/coreclr/pal/inc/mbusafecrt.h
index cdcc2faabeed4..3ea804f09ad8a 100644
--- a/src/coreclr/pal/inc/mbusafecrt.h
+++ b/src/coreclr/pal/inc/mbusafecrt.h
@@ -81,7 +81,6 @@ extern errno_t _makepath_s( char* outDest, size_t inDestBufferSize, const char*
 extern errno_t _wmakepath_s( WCHAR* outDest, size_t inDestBufferSize, const WCHAR* inDrive, const WCHAR* inDirectory, const WCHAR* inFilename, const WCHAR* inExtension );
 
 extern errno_t _splitpath_s( const char* inPath, char* outDrive, size_t inDriveSize, char* outDirectory, size_t inDirectorySize, char* outFilename, size_t inFilenameSize, char* outExtension, size_t inExtensionSize );
-extern errno_t _wsplitpath_s( const WCHAR* inPath, WCHAR* outDrive, size_t inDriveSize, WCHAR* outDirectory, size_t inDirectorySize, WCHAR* outFilename, size_t inFilenameSize, WCHAR* outExtension, size_t inExtensionSize );
 
 extern int sprintf_s( char *string, size_t sizeInBytes, const char *format, ... );
 
diff --git a/src/coreclr/pal/inc/rt/safecrt.h b/src/coreclr/pal/inc/rt/safecrt.h
index 4d9d1a176950c..007b3deae7e1d 100644
--- a/src/coreclr/pal/inc/rt/safecrt.h
+++ b/src/coreclr/pal/inc/rt/safecrt.h
@@ -383,7 +383,6 @@ void __cdecl _invalid_parameter(const WCHAR *_Message, const WCHAR *_FunctionNam
 #define _tcsnset_s      _wcsnset_s
 #define _tcstok_s       wcstok_s
 #define _tmakepath_s    _wmakepath_s
-#define _tsplitpath_s   _wsplitpath_s
 #define _stprintf_s     swprintf_s
 #define _tscanf_s       wscanf_s
 #define _tsscanf_s      swscanf_s
@@ -1370,13 +1369,13 @@ errno_t __cdecl _wmakepath_s(WCHAR *_Dst, size_t _SizeInWords, const WCHAR *_Dri
         } while (*p != 0);
 
         p = p - 1;
-        if (*p != L'/' && *p != L'\\')
+        if (*p != L'/')
         {
             if(++written >= _SizeInWords)
             {
                 goto error_return;
             }
-            *d++ = L'\\';
+            *d++ = L'/';
         }
     }
 
@@ -1432,224 +1431,6 @@ errno_t __cdecl _wmakepath_s(WCHAR *_Dst, size_t _SizeInWords, const WCHAR *_Dri
 }
 #endif
 
-/* _wsplitpath_s */
-_SAFECRT__EXTERN_C
-errno_t __cdecl _wsplitpath_s(
-    const WCHAR *_Path,
-    WCHAR *_Drive, size_t _DriveSize,
-    WCHAR *_Dir, size_t _DirSize,
-    WCHAR *_Filename, size_t _FilenameSize,
-    WCHAR *_Ext, size_t _ExtSize
-);
-
-/* no C++ overload for _wsplitpath_s */
-
-#if _SAFECRT_USE_INLINES || _SAFECRT_IMPL
-
-_SAFECRT__INLINE
-errno_t __cdecl _wsplitpath_s(
-    const WCHAR *_Path,
-    WCHAR *_Drive, size_t _DriveSize,
-    WCHAR *_Dir, size_t _DirSize,
-    WCHAR *_Filename, size_t _FilenameSize,
-    WCHAR *_Ext, size_t _ExtSize
-)
-{
-    const WCHAR *tmp;
-    const WCHAR *last_slash;
-    const WCHAR *dot;
-    int drive_set = 0;
-    size_t length = 0;
-    int bEinval = 0;
-
-    /* validation section */
-    _SAFECRT__VALIDATE_POINTER(_Path);
-    if ((_Drive == nullptr && _DriveSize != 0) || (_Drive != nullptr && _DriveSize == 0))
-    {
-        goto error_einval;
-    }
-    if ((_Dir == nullptr && _DirSize != 0) || (_Dir != nullptr && _DirSize == 0))
-    {
-        goto error_einval;
-    }
-    if ((_Filename == nullptr && _FilenameSize != 0) || (_Filename != nullptr && _FilenameSize == 0))
-    {
-        goto error_einval;
-    }
-    if ((_Ext == nullptr && _ExtSize != 0) || (_Ext != nullptr && _ExtSize == 0))
-    {
-        goto error_einval;
-    }
-
-    /* check if _Path begins with the longpath prefix */
-    if (_Path[0] == L'\\' && _Path[1] == L'\\' && _Path[2] == L'?' && _Path[3] == L'\\')
-    {
-        _Path += 4;
-    }
-
-    /* extract drive letter and ':', if any */
-    if (!drive_set)
-    {
-        size_t skip = _MAX_DRIVE - 2;
-        tmp = _Path;
-        while (skip > 0 && *tmp != 0)
-        {
-            skip--;
-            tmp++;
-        }
-        if (*tmp == L':')
-        {
-            if (_Drive != nullptr)
-            {
-                if (_DriveSize < _MAX_DRIVE)
-                {
-                    goto error_erange;
-                }
-                wcsncpy_s(_Drive, _DriveSize, _Path, _MAX_DRIVE - 1);
-            }
-            _Path = tmp + 1;
-        }
-        else
-        {
-            if (_Drive != nullptr)
-            {
-                _SAFECRT__RESET_STRING(_Drive, _DriveSize);
-            }
-        }
-    }
-
-    /* extract path string, if any. _Path now points to the first character
-     * of the path, if any, or the filename or extension, if no path was
-     * specified.  Scan ahead for the last occurrence, if any, of a '/' or
-     * '\' path separator character.  If none is found, there is no path.
-     * We will also note the last '.' character found, if any, to aid in
-     * handling the extension.
-     */
-    last_slash = nullptr;
-    dot = nullptr;
-    tmp = _Path;
-    for (; *tmp != 0; ++tmp)
-    {
-        {
-            if (*tmp == L'/' || *tmp == L'\\')
-            {
-                /* point to one beyond for later copy */
-                last_slash = tmp + 1;
-            }
-            else if (*tmp == L'.')
-            {
-                dot = tmp;
-            }
-        }
-    }
-
-    if (last_slash != nullptr)
-    {
-        /* found a path - copy up through last_slash or max characters
-         * allowed, whichever is smaller
-         */
-        if (_Dir != nullptr) {
-            length = (size_t)(last_slash - _Path);
-            if (_DirSize <= length)
-            {
-                goto error_erange;
-            }
-            wcsncpy_s(_Dir, _DirSize, _Path, length);
-        }
-        _Path = last_slash;
-    }
-    else
-    {
-        /* there is no path */
-        if (_Dir != nullptr)
-        {
-            _SAFECRT__RESET_STRING(_Dir, _DirSize);
-        }
-    }
-
-    /* extract file name and extension, if any.  Path now points to the
-     * first character of the file name, if any, or the extension if no
-     * file name was given.  Dot points to the '.' beginning the extension,
-     * if any.
-     */
-    if (dot != nullptr && (dot >= _Path))
-    {
-        /* found the marker for an extension - copy the file name up to the '.' */
-        if (_Filename)
-        {
-            length = (size_t)(dot - _Path);
-            if (_FilenameSize <= length)
-            {
-                goto error_erange;
-            }
-            wcsncpy_s(_Filename, _FilenameSize, _Path, length);
-        }
-        /* now we can get the extension - remember that tmp still points
-         * to the terminating nullptr character of path.
-         */
-        if (_Ext)
-        {
-            length = (size_t)(tmp - dot);
-            if (_ExtSize <= length)
-            {
-                goto error_erange;
-            }
-            wcsncpy_s(_Ext, _ExtSize, dot, length);
-        }
-    }
-    else
-    {
-        /* found no extension, give empty extension and copy rest of
-         * string into fname.
-         */
-        if (_Filename)
-        {
-            length = (size_t)(tmp - _Path);
-            if (_FilenameSize <= length)
-            {
-                goto error_erange;
-            }
-            wcsncpy_s(_Filename, _FilenameSize, _Path, length);
-        }
-        if (_Ext)
-        {
-            _SAFECRT__RESET_STRING(_Ext, _ExtSize);
-        }
-    }
-
-    return 0;
-
-error_einval:
-    bEinval = 1;
-
-error_erange:
-    if (_Drive != nullptr && _DriveSize > 0)
-    {
-        _SAFECRT__RESET_STRING(_Drive, _DriveSize);
-    }
-    if (_Dir != nullptr && _DirSize > 0)
-    {
-        _SAFECRT__RESET_STRING(_Dir, _DirSize);
-    }
-    if (_Filename != nullptr && _FilenameSize > 0)
-    {
-        _SAFECRT__RESET_STRING(_Filename, _FilenameSize);
-    }
-    if (_Ext != nullptr && _ExtSize > 0)
-    {
-        _SAFECRT__RESET_STRING(_Ext, _ExtSize);
-    }
-
-    if (bEinval)
-    {
-        _SAFECRT__RETURN_EINVAL;
-    }
-
-    _SAFECRT__RETURN_BUFFER_TOO_SMALL(_Strings, _StringSizes);
-    /* should never happen, but compiler can't tell */
-    return EINVAL;
-}
-#endif
 
 /* vsprintf_s */
 /*
diff --git a/src/coreclr/pal/src/CMakeLists.txt b/src/coreclr/pal/src/CMakeLists.txt
index 9df78198ca634..d9726460ccfe4 100644
--- a/src/coreclr/pal/src/CMakeLists.txt
+++ b/src/coreclr/pal/src/CMakeLists.txt
@@ -201,7 +201,6 @@ set(SOURCES
   safecrt/wcsncpy_s.cpp
   safecrt/wcstok_s.cpp
   safecrt/wmakepath_s.cpp
-  safecrt/wsplitpath_s.cpp
   safecrt/xtoa_s.cpp
   safecrt/xtow_s.cpp
   sharedmemory/sharedmemory.cpp
diff --git a/src/coreclr/pal/src/cruntime/file.cpp b/src/coreclr/pal/src/cruntime/file.cpp
index c92f22af18115..a7a7a12a33375 100644
--- a/src/coreclr/pal/src/cruntime/file.cpp
+++ b/src/coreclr/pal/src/cruntime/file.cpp
@@ -234,8 +234,6 @@ PAL_fopen(const char * fileName, const char * mode)
             goto done;
         }
 
-        FILEDosToUnixPathA( UnixFileName );
-
         /*I am not checking for the case where stat fails
          *as fopen will handle the error more gracefully in case
          *UnixFileName is invalid*/
diff --git a/src/coreclr/pal/src/file/directory.cpp b/src/coreclr/pal/src/file/directory.cpp
index a19e517932dd1..e30fd2d923626 100644
--- a/src/coreclr/pal/src/file/directory.cpp
+++ b/src/coreclr/pal/src/file/directory.cpp
@@ -131,8 +131,6 @@ RemoveDirectoryHelper (
     BOOL  bRet = FALSE;
     *dwLastError = 0;
 
-    FILEDosToUnixPathA( lpPathName );
-
     if ( rmdir(lpPathName) != 0 )
     {
         TRACE("Removal of directory [%s] was unsuccessful, errno = %d.\n",
@@ -415,7 +413,6 @@ CreateDirectoryA(
         dwLastError = ERROR_NOT_ENOUGH_MEMORY;
         goto done;
     }
-    FILEDosToUnixPathA( unixPathName );
     // Remove any trailing slashes at the end because mkdir might not
     // handle them appropriately on all platforms.
     pathLength = strlen(unixPathName);
@@ -509,7 +506,6 @@ SetCurrentDirectoryA(
     BOOL bRet = FALSE;
     DWORD dwLastError = 0;
     int result;
-    LPSTR unixPathName = NULL;
 
     PERF_ENTRY(SetCurrentDirectoryA);
     ENTRY("SetCurrentDirectoryA(lpPathName=%p (%s))\n",
@@ -525,17 +521,8 @@ SetCurrentDirectoryA(
         goto done;
     }
 
-    unixPathName = PAL__strdup(lpPathName);
-    if (unixPathName == NULL )
-    {
-        ERROR("PAL__strdup() failed\n");
-        dwLastError = ERROR_NOT_ENOUGH_MEMORY;
-        goto done;
-    }
-    FILEDosToUnixPathA( unixPathName );
-
-    TRACE("Attempting to open Unix dir [%s]\n", unixPathName);
-    result = chdir(unixPathName);
+    TRACE("Attempting to open Unix dir [%s]\n", lpPathName);
+    result = chdir(lpPathName);
 
     if ( result == 0 )
     {
@@ -547,7 +534,7 @@ SetCurrentDirectoryA(
         {
             struct stat stat_data;
 
-            if ( stat( unixPathName, &stat_data) == 0 &&
+            if ( stat( lpPathName, &stat_data) == 0 &&
                  (stat_data.st_mode & S_IFMT) == S_IFREG )
             {
                 /* Not a directory, it is a file. */
@@ -555,7 +542,7 @@ SetCurrentDirectoryA(
             }
             else
             {
-                FILEGetProperNotFoundError( unixPathName, &dwLastError );
+                FILEGetProperNotFoundError( lpPathName, &dwLastError );
             }
             TRACE("chdir() failed, path was invalid.\n");
         }
@@ -573,11 +560,6 @@ SetCurrentDirectoryA(
         SetLastError(dwLastError);
     }
 
-    if(unixPathName != NULL)
-    {
-        PAL_free( unixPathName );
-    }
-
     LOGEXIT("SetCurrentDirectoryA returns BOOL %d\n", bRet);
     PERF_EXIT(SetCurrentDirectoryA);
     return bRet;
diff --git a/src/coreclr/pal/src/file/file.cpp b/src/coreclr/pal/src/file/file.cpp
index e6e13bbc21360..a15be4dba7418 100644
--- a/src/coreclr/pal/src/file/file.cpp
+++ b/src/coreclr/pal/src/file/file.cpp
@@ -461,8 +461,6 @@ CorUnix::InternalCreateFile(
         goto done;
     }
 
-    FILEDosToUnixPathA( lpUnixPath );
-
     // Compute the absolute pathname to the file.  This pathname is used
     // to determine if two file names represent the same file.
     palError = InternalCanonicalizeRealPath(lpUnixPath, lpFullUnixPath);
@@ -1031,8 +1029,6 @@ DeleteFileA(
         goto done;
     }
 
-    FILEDosToUnixPathA( lpunixFileName );
-
     // Compute the absolute pathname to the file.  This pathname is used
     // to determine if two file names represent the same file.
     palError = InternalCanonicalizeRealPath(lpunixFileName, lpFullunixFileName);
@@ -1103,7 +1099,6 @@ GetFileAttributesA(
     struct stat stat_data;
     DWORD dwAttr = 0;
     DWORD dwLastError = 0;
-    PathCharString unixFileName;
 
     PERF_ENTRY(GetFileAttributesA);
     ENTRY("GetFileAttributesA(lpFileName=%p (%s))\n", lpFileName?lpFileName:"NULL", lpFileName?lpFileName:"NULL");
@@ -1115,18 +1110,9 @@ GetFileAttributesA(
         goto done;
     }
 
-
-    if( !unixFileName.Set(lpFileName, strlen(lpFileName)))
-    {
-        dwLastError = ERROR_NOT_ENOUGH_MEMORY;
-        goto done;
-    }
-
-    FILEDosToUnixPathA( unixFileName );
-
-    if ( stat(unixFileName, &stat_data) != 0 )
+    if ( stat(lpFileName, &stat_data) != 0 )
     {
-        dwLastError = FILEGetLastErrorFromErrnoAndFilename(unixFileName);
+        dwLastError = FILEGetLastErrorFromErrnoAndFilename(lpFileName);
         goto done;
     }
 
@@ -1311,7 +1297,6 @@ GetFileAttributesExW(
         goto done;
     }
 
-    FILEDosToUnixPathA(name);
     /* do the stat */
     if ( stat(name, &stat_data) != 0 )
     {
@@ -1386,7 +1371,6 @@ SetFileAttributesA(
 
     DWORD dwLastError = 0;
     BOOL  bRet = FALSE;
-    LPSTR unixFileName = NULL;
 
     PERF_ENTRY(SetFileAttributesA);
     ENTRY("SetFileAttributesA(lpFileName=%p (%s), dwFileAttributes=%#x)\n",
@@ -1422,19 +1406,11 @@ SetFileAttributesA(
         goto done;
     }
 
-    if ((unixFileName = strdup(lpFileName)) == NULL)
-    {
-        ERROR("strdup() failed\n");
-        dwLastError = ERROR_NOT_ENOUGH_MEMORY;
-        goto done;
-    }
-
-    FILEDosToUnixPathA( unixFileName );
-    if ( stat(unixFileName, &stat_data) != 0 )
+    if ( stat(lpFileName, &stat_data) != 0 )
     {
         TRACE("stat failed on %s; errno is %d (%s)\n",
-             unixFileName, errno, strerror(errno));
-        dwLastError = FILEGetLastErrorFromErrnoAndFilename(unixFileName);
+             lpFileName, errno, strerror(errno));
+        dwLastError = FILEGetLastErrorFromErrnoAndFilename(lpFileName);
         goto done;
     }
 
@@ -1470,10 +1446,10 @@ SetFileAttributesA(
     bRet = TRUE;
     if ( new_mode != stat_data.st_mode )
     {
-        if ( chmod(unixFileName, new_mode) != 0 )
+        if ( chmod(lpFileName, new_mode) != 0 )
         {
-            ERROR("chmod(%s, %#x) failed\n", unixFileName, new_mode);
-            dwLastError = FILEGetLastErrorFromErrnoAndFilename(unixFileName);
+            ERROR("chmod(%s, %#x) failed\n", lpFileName, new_mode);
+            dwLastError = FILEGetLastErrorFromErrnoAndFilename(lpFileName);
             bRet = FALSE;
         }
     }
@@ -1484,8 +1460,6 @@ SetFileAttributesA(
         pThread->SetLastError(dwLastError);
     }
 
-    free(unixFileName);
-
     LOGEXIT("SetFileAttributesA returns BOOL %d\n", bRet);
     PERF_EXIT(SetFileAttributesA);
     return bRet;
@@ -2657,16 +2631,15 @@ GetTempFileNameA(
     file_templatePS.CloseBuffer(length);
 
     chLastPathNameChar = file_template[strlen(file_template)-1];
-    if (chLastPathNameChar != '\\' && chLastPathNameChar != '/')
+    if (chLastPathNameChar != '/')
     {
-        strcat_s( file_template, file_templatePS.GetSizeOf(), "\\" );
+        strcat_s( file_template, file_templatePS.GetSizeOf(), "/" );
     }
 
     if ( lpPrefixString )
     {
         strncat_s( file_template, file_templatePS.GetSizeOf(), lpPrefixString, MAX_PREFIX );
     }
-    FILEDosToUnixPathA( file_template );
     strncat_s( file_template, file_templatePS.GetSizeOf(), "%.4x.TMP", MAX_SEEDSIZE );
 
     /* Create the file. */
@@ -3017,7 +2990,6 @@ CopyFileA(
     DWORD        dwSrcFileAttributes;
     struct stat  SrcFileStats;
 
-    LPSTR lpUnixPath = NULL;
     const int    buffer_size = 16*1024;
     char        *buffer = (char*)alloca(buffer_size);
     DWORD        bytes_read;
@@ -3065,18 +3037,10 @@ CopyFileA(
     }
 
     /* Need to preserve the owner/group and chmod() flags */
-    lpUnixPath = strdup(lpExistingFileName);
-    if ( lpUnixPath == NULL )
-    {
-        ERROR("strdup() failed\n");
-        pThread->SetLastError(FILEGetLastErrorFromErrno());
-        goto done;
-    }
-    FILEDosToUnixPathA(lpUnixPath);
-    if (stat (lpUnixPath, &SrcFileStats) == -1)
+    if (stat (lpExistingFileName, &SrcFileStats) == -1)
     {
         ERROR("stat() failed for %s\n", lpExistingFileName);
-        pThread->SetLastError(FILEGetLastErrorFromErrnoAndFilename(lpUnixPath));
+        pThread->SetLastError(FILEGetLastErrorFromErrnoAndFilename(lpExistingFileName));
         goto done;
     }
 
@@ -3094,17 +3058,6 @@ CopyFileA(
         goto done;
     }
 
-    free(lpUnixPath);
-    lpUnixPath = strdup(lpNewFileName);
-    if ( lpUnixPath == NULL )
-    {
-        ERROR("strdup() failed\n");
-        pThread->SetLastError(FILEGetLastErrorFromErrno());
-        goto done;
-    }
-    FILEDosToUnixPathA( lpUnixPath );
-
-
     // We don't set file attributes in CreateFile. The only attribute
     // that is reflected on disk in Unix is read-only, and we set that
     // here.
@@ -3115,11 +3068,11 @@ CopyFileA(
     }
 
     /* Make sure the new file has the same chmod() flags. */
-    if (chmod(lpUnixPath, SrcFileStats.st_mode & permissions) == -1)
+    if (chmod(lpNewFileName, SrcFileStats.st_mode & permissions) == -1)
     {
         WARN ("chmod() failed to set mode 0x%x on new file\n",
               SrcFileStats.st_mode & permissions);
-        pThread->SetLastError(FILEGetLastErrorFromErrnoAndFilename(lpUnixPath));
+        pThread->SetLastError(FILEGetLastErrorFromErrnoAndFilename(lpNewFileName));
         goto done;
     }
 
@@ -3155,10 +3108,6 @@ CopyFileA(
     {
         CloseHandle( hDest );
     }
-    if (lpUnixPath)
-    {
-        free(lpUnixPath);
-    }
 
     LOGEXIT("CopyFileA returns BOOL %d\n", bGood);
     PERF_EXIT(CopyFileA);
diff --git a/src/coreclr/pal/src/file/find.cpp b/src/coreclr/pal/src/file/find.cpp
index 8f2431abfa98c..b874885992f8c 100644
--- a/src/coreclr/pal/src/file/find.cpp
+++ b/src/coreclr/pal/src/file/find.cpp
@@ -177,7 +177,6 @@ FindFirstFileA(
                 SetLastError( ERROR_INTERNAL_ERROR );
                 goto done;
             }
-            FILEDosToUnixPathA( lpTemp );
             FILEGetProperNotFoundError( lpTemp, &dwLastError );
 
             if ( ERROR_PATH_NOT_FOUND == dwLastError )
@@ -909,11 +908,6 @@ static BOOL FILEDosGlobA( CPalThread *pthrCurrent,
         goto done;
     }
 
-    if (Dir[0] != 0)
-    {
-         FILEDosToUnixPathA( Dir );
-    }
-
     /* The meat of the routine happens below. Basically, there are three
        special things to check for:
 
diff --git a/src/coreclr/pal/src/file/path.cpp b/src/coreclr/pal/src/file/path.cpp
index 5de7ce43c70ff..92383dd204ace 100644
--- a/src/coreclr/pal/src/file/path.cpp
+++ b/src/coreclr/pal/src/file/path.cpp
@@ -73,7 +73,7 @@ GetFullPathNameA(
     }
 
     /* find out if lpFileName is a partial or full path */
-    if ('\\' == *lpFileName || '/' == *lpFileName)
+    if ('/' == *lpFileName)
     {
         fullPath = TRUE;
     }
@@ -112,8 +112,6 @@ GetFullPathNameA(
     }
 
     unixPathBuf = unixPath.OpenStringBuffer(unixPath.GetCount());
-    /* do conversion to Unix path */
-    FILEDosToUnixPathA( unixPathBuf );
 
     /* now we can canonicalize this */
     FILECanonicalizePath(unixPathBuf);
@@ -433,57 +431,6 @@ GetTempPathW(
 }
 
 
-
-/*++
-Function:
-  FileDosToUnixPathA
-
-Abstract:
-  Change a DOS path to a Unix path.
-
-  Replaces '\' by '/'
-
-Parameter:
-  IN/OUT lpPath: path to be modified
---*/
-void
-FILEDosToUnixPathA(
-       LPSTR lpPath)
-{
-    LPSTR p;
-
-    TRACE("Original DOS path = [%s]\n", lpPath);
-
-    if (!lpPath)
-    {
-        return;
-    }
-
-    for (p = lpPath; *p; p++)
-    {
-        /* Replace \ with / */
-        if (*p == '\\')
-        {
-            *p = '/';
-        }
-    }
-
-    TRACE("Resulting Unix path = [%s]\n", lpPath);
-}
-
-void
-FILEDosToUnixPathA(
-       PathCharString&  lpPath)
-{
-
-    SIZE_T len = lpPath.GetCount();
-    LPSTR lpPathBuf = lpPath.OpenStringBuffer(len);
-    FILEDosToUnixPathA(lpPathBuf);
-    lpPath.CloseBuffer(len);
-
-}
-
-
 /*++
 Function:
   FILEGetDirectoryFromFullPathA
@@ -506,7 +453,7 @@ DWORD FILEGetDirectoryFromFullPathA( LPCSTR lpFullPath,
 
     /* look for the first path separator backwards */
     lpDirEnd = lpFullPath + full_len - 1;
-    while( lpDirEnd >= lpFullPath && *lpDirEnd != '/' && *lpDirEnd != '\\')
+    while( lpDirEnd >= lpFullPath && *lpDirEnd != '/')
     --lpDirEnd;
 
     dir_len = lpDirEnd - lpFullPath + 1; /* +1 for fencepost */
@@ -734,7 +681,7 @@ SearchPathW(
 
     /* special case : if file name contains absolute path, don't search the
        provided path */
-    if('\\' == lpFileName[0] || '/' == lpFileName[0])
+    if(L'/' == lpFileName[0])
     {
         /* Canonicalize the path to deal with back-to-back '/', etc. */
         length = MAX_LONGPATH; //Use it for first try
diff --git a/src/coreclr/pal/src/include/pal/file.h b/src/coreclr/pal/src/include/pal/file.h
index d56d5df8b62a4..52054306cb3a6 100644
--- a/src/coreclr/pal/src/include/pal/file.h
+++ b/src/coreclr/pal/src/include/pal/file.h
@@ -59,19 +59,6 @@ Notes :
 --*/
 void FILECanonicalizePath(LPSTR lpUnixPath);
 
-/*++
-Function:
-  FileDosToUnixPathA
-
-Abstract:
-  Change a DOS path to a Unix path. Replace '\' by '/'.
-
-Parameter:
-  IN/OUT lpPath: path to be modified
---*/
-void
-FILEDosToUnixPathA(LPSTR lpPath);
-
 /*++
 Function:
   FILEGetDirectoryFromFullPathA
diff --git a/src/coreclr/pal/src/include/pal/file.hpp b/src/coreclr/pal/src/include/pal/file.hpp
index e45607d0bc1dd..c35aa5cbeb86d 100644
--- a/src/coreclr/pal/src/include/pal/file.hpp
+++ b/src/coreclr/pal/src/include/pal/file.hpp
@@ -190,19 +190,6 @@ Notes :
 --*/
 void FILECanonicalizePath(LPSTR lpUnixPath);
 
-/*++
-Function:
-  FileDosToUnixPathA
-
-Abstract:
-  Change a DOS path to a Unix path. Replace '\' by '/'.
-
-Parameter:
-  IN/OUT lpPath: path to be modified
---*/
-void
-FILEDosToUnixPathA(LPSTR lpPath);
-
 /*++
 Function:
   FILEGetDirectoryFromFullPathA
diff --git a/src/coreclr/pal/src/include/pal/stackstring.hpp b/src/coreclr/pal/src/include/pal/stackstring.hpp
index 38c4b84b6672c..4a27a15579c7d 100644
--- a/src/coreclr/pal/src/include/pal/stackstring.hpp
+++ b/src/coreclr/pal/src/include/pal/stackstring.hpp
@@ -256,6 +256,3 @@ typedef StackString<MAX_PATH, WCHAR> PathWCharString;
 DWORD
 GetCurrentDirectoryA(
          PathCharString& lpBuffer);
-void
-FILEDosToUnixPathA(
-        PathCharString& lpPath);
diff --git a/src/coreclr/pal/src/loader/module.cpp b/src/coreclr/pal/src/loader/module.cpp
index 838fe3d793e2a..ce443f0dfc3c3 100644
--- a/src/coreclr/pal/src/loader/module.cpp
+++ b/src/coreclr/pal/src/loader/module.cpp
@@ -152,7 +152,6 @@ LoadLibraryExA(
         return nullptr;
     }
 
-    LPSTR lpstr = nullptr;
     HMODULE hModule = nullptr;
 
     PERF_ENTRY(LoadLibraryA);
@@ -166,23 +165,10 @@ LoadLibraryExA(
     }
 
     /* do the Dos/Unix conversion on our own copy of the name */
-    lpstr = strdup(lpLibFileName);
-    if (!lpstr)
-    {
-        ERROR("strdup failure!\n");
-        SetLastError(ERROR_NOT_ENOUGH_MEMORY);
-        goto Done;
-    }
-    FILEDosToUnixPathA(lpstr);
-
-    hModule = LOADLoadLibrary(lpstr, TRUE);
+    hModule = LOADLoadLibrary(lpLibFileName, TRUE);
 
     /* let LOADLoadLibrary call SetLastError */
  Done:
-    if (lpstr != nullptr)
-    {
-        free(lpstr);
-    }
 
     LOGEXIT("LoadLibraryExA returns HMODULE %p\n", hModule);
     PERF_EXIT(LoadLibraryExA);
@@ -235,8 +221,6 @@ LoadLibraryExW(
         goto done;
     }
 
-    /* do the Dos/Unix conversion on our own copy of the name */
-    FILEDosToUnixPathA(lpstr);
     pathstr.CloseBuffer(name_length);
 
     /* let LOADLoadLibrary call SetLastError in case of failure */
@@ -626,8 +610,6 @@ PAL_LoadLibraryDirect(
         goto done;
     }
 
-    /* do the Dos/Unix conversion on our own copy of the name */
-    FILEDosToUnixPathA(lpstr);
     pathstr.CloseBuffer(name_length);
     lpcstr = FixLibCName(lpstr);
 
diff --git a/src/coreclr/pal/src/safecrt/tmakepath_s.inl b/src/coreclr/pal/src/safecrt/tmakepath_s.inl
index 53517412f75e9..aabf7ee266c10 100644
--- a/src/coreclr/pal/src/safecrt/tmakepath_s.inl
+++ b/src/coreclr/pal/src/safecrt/tmakepath_s.inl
@@ -48,13 +48,13 @@ errno_t __cdecl _FUNC_NAME(_Out_writes_z_(_SIZE) _CHAR *_DEST, _In_opt_ size_t _
         } while (*p != 0);
 
         p--;
-        if (*p != _T('/') && *p != _T('\\'))
+        if (*p != '/')
         {
             if(++written >= _SIZE)
             {
                 goto error_return;
             }
-            *d++ = _T('\\');
+            *d++ = '/';
         }
     }
 
diff --git a/src/coreclr/pal/src/safecrt/tsplitpath_s.inl b/src/coreclr/pal/src/safecrt/tsplitpath_s.inl
index 4366ec3cebbfa..c3d8b41403882 100644
--- a/src/coreclr/pal/src/safecrt/tsplitpath_s.inl
+++ b/src/coreclr/pal/src/safecrt/tsplitpath_s.inl
@@ -102,7 +102,7 @@ errno_t __cdecl _FUNC_NAME(
     tmp = _Path;
     for (; *tmp != 0; ++tmp)
     {
-        if (*tmp == _T('/') || *tmp == _T('\\'))
+        if (*tmp == '/')
         {
             /* point to one beyond for later copy */
             last_slash = tmp + 1;
@@ -125,16 +125,6 @@ errno_t __cdecl _FUNC_NAME(
                 goto error_erange;
             }
             _TCSNCPY_S(_Dir, _DirSize, _Path, length);
-
-            // Normalize the path separator
-            size_t iIndex;
-            for(iIndex = 0; iIndex < length; iIndex++)
-            {
-                if (_Dir[iIndex] == _T('\\'))
-                {
-                    _Dir[iIndex] = _T('/');
-                }
-            }
         }
         _Path = last_slash;
     }
diff --git a/src/coreclr/pal/src/safecrt/wsplitpath_s.cpp b/src/coreclr/pal/src/safecrt/wsplitpath_s.cpp
deleted file mode 100644
index 420d7134acaf1..0000000000000
--- a/src/coreclr/pal/src/safecrt/wsplitpath_s.cpp
+++ /dev/null
@@ -1,28 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-/***
-*wsplitpath_s.c - break down path name into components
-*
-
-*
-*Purpose:
-*   To provide support for accessing the individual components of an
-*   arbitrary path name
-*
-*******************************************************************************/
-
-#include <string.h>
-#include <errno.h>
-#include <limits.h>
-#include "internal_securecrt.h"
-
-#include "mbusafecrt_internal.h"
-
-#define _FUNC_PROLOGUE
-#define _FUNC_NAME _wsplitpath_s
-#define _CHAR char16_t
-#define _TCSNCPY_S wcsncpy_s
-#define _T(_Character) L##_Character
-
-#include "tsplitpath_s.inl"
diff --git a/src/coreclr/pal/src/thread/process.cpp b/src/coreclr/pal/src/thread/process.cpp
index 8f93db9f95c1d..29b82b69d383f 100644
--- a/src/coreclr/pal/src/thread/process.cpp
+++ b/src/coreclr/pal/src/thread/process.cpp
@@ -3417,8 +3417,7 @@ getFileName(
                                             NULL, 0, NULL, NULL);
 
         /* if only a file name is specified, prefix it with "./" */
-        if ((*lpApplicationName != '.') && (*lpApplicationName != '/') &&
-            (*lpApplicationName != '\\'))
+        if ((*lpApplicationName != '.') && (*lpApplicationName != '/'))
         {
             length += 2;
             lpTemp = lpPathFileName.OpenStringBuffer(length);
@@ -3448,9 +3447,6 @@ getFileName(
 
         lpPathFileName.CloseBuffer(length -1);
 
-        /* Replace '\' by '/' */
-        FILEDosToUnixPathA(lpTemp);
-
         return TRUE;
     }
     else
@@ -3521,8 +3517,6 @@ getFileName(
         /* restore last character */
         *lpEnd = wcEnd;
 
-        /* Replace '\' by '/' */
-        FILEDosToUnixPathA(lpFileName);
         if (!getPath(lpFileNamePS, lpPathFileName))
         {
             /* file is not in the path */
diff --git a/src/coreclr/pal/tests/palsuite/common/palsuite.cpp b/src/coreclr/pal/tests/palsuite/common/palsuite.cpp
index 5e02d5e709fca..f8bcb0727af17 100644
--- a/src/coreclr/pal/tests/palsuite/common/palsuite.cpp
+++ b/src/coreclr/pal/tests/palsuite/common/palsuite.cpp
@@ -62,7 +62,7 @@ UINT64 GetHighPrecisionTimeStamp(LARGE_INTEGER performanceFrequency)
     return ts.QuadPart / (performanceFrequency.QuadPart / 1000);    
 }
 
-static const char* rgchPathDelim = "\\";
+static const char* rgchPathDelim = "/";
 
 
 int
@@ -146,7 +146,7 @@ mkAbsoluteFilenameW (
     DWORD dwFileLength,
     LPWSTR absPathName )
 {
-    const WCHAR szPathDelimW[] = {'\\','\0'};
+    const WCHAR szPathDelimW[] = {'/','\0'};
 
     DWORD sizeDN, sizeFN, sizeAPN;
 
diff --git a/src/coreclr/pal/tests/palsuite/file_io/GetFullPathNameA/test3/test3.cpp b/src/coreclr/pal/tests/palsuite/file_io/GetFullPathNameA/test3/test3.cpp
index e8f481d7114e0..350d187e3950e 100644
--- a/src/coreclr/pal/tests/palsuite/file_io/GetFullPathNameA/test3/test3.cpp
+++ b/src/coreclr/pal/tests/palsuite/file_io/GetFullPathNameA/test3/test3.cpp
@@ -35,10 +35,10 @@ PALTEST(file_io_GetFullPathNameA_test3_paltest_getfullpathnamea_test3, "file_io/
 #ifdef WIN32
     const char* szSeparator = "\\";
 #else
-    const char* szSeparator = "//";
+    const char* szSeparator = "/";
 #endif
 
-    const char* szDotDot   = "..\\";
+    const char* szDotDot   = "../";
     const char* szFileName = "testing.tmp";
 
     DWORD   dwRc = 0;
diff --git a/src/coreclr/pal/tests/palsuite/file_io/GetFullPathNameW/test2/test2.cpp b/src/coreclr/pal/tests/palsuite/file_io/GetFullPathNameW/test2/test2.cpp
index 57fa29130c64c..2ed9e1279f487 100644
--- a/src/coreclr/pal/tests/palsuite/file_io/GetFullPathNameW/test2/test2.cpp
+++ b/src/coreclr/pal/tests/palsuite/file_io/GetFullPathNameW/test2/test2.cpp
@@ -18,7 +18,7 @@
 
 PALTEST(file_io_GetFullPathNameW_test2_paltest_getfullpathnamew_test2, "file_io/GetFullPathNameW/test2/paltest_getfullpathnamew_test2")
 {
-    WCHAR szwDotDot[]   = {'.','.','\\','\0'};
+    WCHAR szwDotDot[]   = {'.','.','/','\0'};
     WCHAR szwFileName[] = {'t','e','s','t','i','n','g','.','t','m','p','\0'};
 
     DWORD dwRc = 0;
diff --git a/src/coreclr/pal/tests/palsuite/file_io/GetTempFileNameW/test1/GetTempFileNameW.cpp b/src/coreclr/pal/tests/palsuite/file_io/GetTempFileNameW/test1/GetTempFileNameW.cpp
index f1be5b6652579..02a01a4fe7534 100644
--- a/src/coreclr/pal/tests/palsuite/file_io/GetTempFileNameW/test1/GetTempFileNameW.cpp
+++ b/src/coreclr/pal/tests/palsuite/file_io/GetTempFileNameW/test1/GetTempFileNameW.cpp
@@ -106,8 +106,8 @@ PALTEST(file_io_GetTempFileNameW_test1_paltest_gettempfilenamew_test1, "file_io/
         WCHAR* wCurr = wTempString;
         memcpy(wCurr, wPath, wcslen(wPath) * sizeof(WCHAR));
         wCurr += wcslen(wPath);
-        wcscat(wCurr, W("\\"));
-        wCurr += wcslen(W("\\"));
+        wcscat(wCurr, W("/"));
+        wCurr += wcslen(W("/"));
         wcscat(wCurr, wPrefix);
         if (memcmp(wTempString, wReturnedName, wcslen(wTempString)*sizeof(WCHAR)) == 0)
         {
diff --git a/src/coreclr/tools/metainfo/mdobj.cpp b/src/coreclr/tools/metainfo/mdobj.cpp
index 5bb4689410bb0..8102b95bd2d62 100644
--- a/src/coreclr/tools/metainfo/mdobj.cpp
+++ b/src/coreclr/tools/metainfo/mdobj.cpp
@@ -272,21 +272,26 @@ void DisplayFile(_In_z_ WCHAR* szFile, BOOL isFile, ULONG DumpFilter, _In_opt_z_
 
     // print bar that separates different files
     pDisplayString("////////////////////////////////////////////////////////////////\n");
-    WCHAR rcFname[_MAX_FNAME], rcExt[_MAX_EXT];
 
-    _wsplitpath_s(szFile, NULL, 0, NULL, 0, rcFname, _MAX_FNAME, rcExt, _MAX_EXT);
-    sprintf_s(szString,1024,"\nFile %S%S: \n",rcFname, rcExt);
+    WCHAR *pExt = wcsrchr(szFile, W('.'));
+    WCHAR *pFname = wcsrchr(szFile, DIRECTORY_SEPARATOR_CHAR_W);
+    if (pFname == NULL)
+    {
+        pFname = szFile;
+    }
+
+    sprintf_s(szString,1024,"\nFile %S: \n",pFname);
     pDisplayString(szString);
 
     if (DumpFilter & MDInfo::dumpValidate)
     {
-        if (!_wcsicmp(rcExt, OBJ_EXT_W) || !_wcsicmp(rcExt, LIB_EXT_W))
+        if (pExt && (!_wcsicmp(pExt, OBJ_EXT_W) || !_wcsicmp(pExt, LIB_EXT_W)))
             g_ValModuleType = ValidatorModuleTypeObj;
         else
             g_ValModuleType = ValidatorModuleTypePE;
     }
 
-    if (!_wcsicmp(rcExt, LIB_EXT_W))
+    if (pExt && !_wcsicmp(pExt, LIB_EXT_W))
         DisplayArchive(szFile, DumpFilter, szObjName, pDisplayString);
     else
     {
diff --git a/src/coreclr/tools/superpmi/mcs/verbmerge.cpp b/src/coreclr/tools/superpmi/mcs/verbmerge.cpp
index 82af9cd63e272..68e89df2e047a 100644
--- a/src/coreclr/tools/superpmi/mcs/verbmerge.cpp
+++ b/src/coreclr/tools/superpmi/mcs/verbmerge.cpp
@@ -349,7 +349,7 @@ int verbMerge::AppendAllInDir(HANDLE              hFileOut,
     {
         const _WIN32_FIND_DATAW& findData     = fileArray[i];
         LPWSTR                   fileFullPath = MergePathStrings(dir, findData.cFileName);
-
+#ifdef TARGET_WINDOWS
         if (wcslen(fileFullPath) > MAX_PATH) // This path is too long, use \\?\ to access it.
         {
             if (wcscmp(dir, W(".")) == 0)
@@ -377,6 +377,7 @@ int verbMerge::AppendAllInDir(HANDLE              hFileOut,
 
             fileFullPath = newBuffer;
         }
+#endif // TARGET_WINDOWS
 
         // Is it zero length? If so, skip it.
         if ((findData.nFileSizeLow == 0) && (findData.nFileSizeHigh == 0))
diff --git a/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h b/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
index c6e102f1d7d15..8c511b45e91b9 100644
--- a/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
+++ b/src/coreclr/tools/superpmi/superpmi-shared/standardpch.h
@@ -82,13 +82,6 @@
 #include "..\external\msvcdis\inc\disarm64.h"
 #endif // USE_MSVCDIS
 
-#ifndef DIRECTORY_SEPARATOR_CHAR_A
-#define DIRECTORY_SEPARATOR_CHAR_A '\\'
-#endif
-#ifndef DIRECTORY_SEPARATOR_STR_A
-#define DIRECTORY_SEPARATOR_STR_A "\\"
-#endif
-
 #ifndef W
 #ifdef TARGET_UNIX
 #define W(str) u##str
@@ -97,9 +90,27 @@
 #endif // TARGET_UNIX
 #endif // !W
 
+#ifdef TARGET_UNIX
+#ifndef DIRECTORY_SEPARATOR_CHAR_A
+#define DIRECTORY_SEPARATOR_CHAR_A '/'
+#endif
+#ifndef DIRECTORY_SEPARATOR_STR_A
+#define DIRECTORY_SEPARATOR_STR_A "/"
+#endif
+#ifndef DIRECTORY_SEPARATOR_STR_W
+#define DIRECTORY_SEPARATOR_STR_W W("/")
+#endif
+#else // TARGET_UNIX
+#ifndef DIRECTORY_SEPARATOR_CHAR_A
+#define DIRECTORY_SEPARATOR_CHAR_A '\\'
+#endif
+#ifndef DIRECTORY_SEPARATOR_STR_A
+#define DIRECTORY_SEPARATOR_STR_A "\\"
+#endif
 #ifndef DIRECTORY_SEPARATOR_STR_W
 #define DIRECTORY_SEPARATOR_STR_W W("\\")
 #endif
+#endif // TARGET_UNIX
 
 #ifdef TARGET_UNIX
 #define PLATFORM_SHARED_LIB_SUFFIX_A PAL_SHLIB_SUFFIX
diff --git a/src/coreclr/tools/superpmi/superpmi/jitdebugger.cpp b/src/coreclr/tools/superpmi/superpmi/jitdebugger.cpp
index 242771fe796c8..44ddfa962c07f 100644
--- a/src/coreclr/tools/superpmi/superpmi/jitdebugger.cpp
+++ b/src/coreclr/tools/superpmi/superpmi/jitdebugger.cpp
@@ -155,7 +155,7 @@ HRESULT GetCurrentModuleFileName(_Out_writes_(*pcchBuffer) LPWSTR pBuffer, __ino
     }
 
     // Pick off the part after the path.
-    WCHAR* appName = wcsrchr(appPath, L'\\');
+    WCHAR* appName = wcsrchr(appPath, DIRECTORY_SEPARATOR_CHAR_W);
 
     // If no backslash, use the whole name; if there is a backslash, skip it.
     appName = appName ? appName + 1 : appPath;
diff --git a/src/coreclr/utilcode/longfilepathwrappers.cpp b/src/coreclr/utilcode/longfilepathwrappers.cpp
index 41635c7084f99..3dea6ad57e8eb 100644
--- a/src/coreclr/utilcode/longfilepathwrappers.cpp
+++ b/src/coreclr/utilcode/longfilepathwrappers.cpp
@@ -7,221 +7,30 @@
 #include "sstring.h"
 #include "ex.h"
 
+#ifdef HOST_WINDOWS
 class LongFile
 {
 private:
-#ifdef HOST_WINDOWS
         static const WCHAR* ExtendedPrefix;
         static const WCHAR* DevicePathPrefix;
         static const WCHAR* UNCPathPrefix;
         static const WCHAR* UNCExtendedPathPrefix;
         static const WCHAR VolumeSeparatorChar;
 		#define UNCPATHPREFIX W("\\\\")
-#endif //HOST_WINDOWS
-        static const WCHAR DirectorySeparatorChar;
         static const WCHAR AltDirectorySeparatorChar;
+        static const WCHAR DirectorySeparatorChar;
 public:
-        static BOOL ContainsDirectorySeparator(SString & path);
         static BOOL IsDirectorySeparator(WCHAR c);
         static BOOL IsPathNotFullyQualified(const SString & path);
 
         static HRESULT NormalizePath(SString& path);
 
-#ifdef HOST_WINDOWS
         static BOOL IsExtended(const SString & path);
         static BOOL IsUNCExtended(const SString & path);
         static BOOL IsDevice(const SString & path);
         static void NormalizeDirectorySeparators(SString& path);
-#endif
 };
-
-HMODULE
-LoadLibraryExWrapper(
-        LPCWSTR lpLibFileName,
-        HANDLE hFile,
-        DWORD dwFlags
-        )
-{
-    CONTRACTL
-    {
-        NOTHROW;
-    }
-    CONTRACTL_END;
-
-    HRESULT hr   = S_OK;
-    HMODULE ret = NULL;
-    DWORD lastError = 0;
-
-    EX_TRY
-    {
-        LongPathString path(LongPathString::Literal, lpLibFileName);
-
-        if (LongFile::IsPathNotFullyQualified(path) || SUCCEEDED(LongFile::NormalizePath(path)))
-        {
-#ifdef HOST_WINDOWS
-            LongFile::NormalizeDirectorySeparators(path);
-#endif //HOST_WINDOWS
-
-            ret = LoadLibraryExW(path.GetUnicode(), hFile, dwFlags);
-        }
-
-        lastError = GetLastError();
-    }
-    EX_CATCH_HRESULT(hr);
-
-    if (hr != S_OK)
-    {
-        SetLastError(hr);
-    }
-    else if(ret == NULL)
-    {
-        SetLastError(lastError);
-    }
-
-    return ret;
-}
-
-HANDLE
-CreateFileWrapper(
-        _In_ LPCWSTR lpFileName,
-        _In_ DWORD dwDesiredAccess,
-        _In_ DWORD dwShareMode,
-        _In_opt_ LPSECURITY_ATTRIBUTES lpSecurityAttributes,
-        _In_ DWORD dwCreationDisposition,
-        _In_ DWORD dwFlagsAndAttributes,
-        _In_opt_ HANDLE hTemplateFile
-        )
-{
-    CONTRACTL
-    {
-        NOTHROW;
-    }
-    CONTRACTL_END;
-
-    HRESULT hr = S_OK;
-    DWORD lastError = 0;
-    HANDLE ret = INVALID_HANDLE_VALUE;
-
-    EX_TRY
-    {
-        LongPathString path(LongPathString::Literal, lpFileName);
-
-        if (SUCCEEDED(LongFile::NormalizePath(path)))
-        {
-            ret = CreateFileW(path.GetUnicode(),
-                    dwDesiredAccess,
-                    dwShareMode,
-                    lpSecurityAttributes,
-                    dwCreationDisposition,
-                    dwFlagsAndAttributes,
-                    hTemplateFile);
-
-        }
-
-        lastError = GetLastError();
-    }
-    EX_CATCH_HRESULT(hr);
-
-    if (hr != S_OK )
-    {
-        SetLastError(hr);
-    }
-    else if(ret == INVALID_HANDLE_VALUE)
-    {
-        SetLastError(lastError);
-    }
-
-    return ret;
-}
-
-DWORD
-GetFileAttributesWrapper(
-        _In_ LPCWSTR lpFileName
-        )
-{
-    CONTRACTL
-    {
-        NOTHROW;
-    }
-    CONTRACTL_END;
-
-    HRESULT hr = S_OK;
-    DWORD  ret = INVALID_FILE_ATTRIBUTES;
-    DWORD lastError = 0;
-
-    EX_TRY
-    {
-        LongPathString path(LongPathString::Literal, lpFileName);
-
-        if (SUCCEEDED(LongFile::NormalizePath(path)))
-        {
-            ret = GetFileAttributesW(
-                    path.GetUnicode()
-                );
-        }
-
-        lastError = GetLastError();
-    }
-    EX_CATCH_HRESULT(hr);
-
-    if (hr != S_OK )
-    {
-        SetLastError(hr);
-    }
-    else if(ret == INVALID_FILE_ATTRIBUTES)
-    {
-        SetLastError(lastError);
-    }
-
-    return ret;
-}
-
-BOOL
-GetFileAttributesExWrapper(
-        _In_ LPCWSTR lpFileName,
-        _In_ GET_FILEEX_INFO_LEVELS fInfoLevelId,
-        _Out_writes_bytes_(sizeof(WIN32_FILE_ATTRIBUTE_DATA)) LPVOID lpFileInformation
-        )
-{
-    CONTRACTL
-    {
-        NOTHROW;
-    }
-    CONTRACTL_END;
-
-    HRESULT hr = S_OK;
-    BOOL   ret = FALSE;
-    DWORD lastError = 0;
-
-    EX_TRY
-    {
-        LongPathString path(LongPathString::Literal, lpFileName);
-
-        if (SUCCEEDED(LongFile::NormalizePath(path)))
-        {
-            ret = GetFileAttributesExW(
-                    path.GetUnicode(),
-                    fInfoLevelId,
-                    lpFileInformation
-                    );
-
-        }
-
-        lastError = GetLastError();
-    }
-    EX_CATCH_HRESULT(hr);
-
-    if (hr != S_OK )
-    {
-        SetLastError(hr);
-    }
-    else if(ret == FALSE)
-    {
-        SetLastError(lastError);
-    }
-
-    return ret;
-}
+#endif // HOST_WINDOWS
 
 DWORD
 SearchPathWrapper(
@@ -245,8 +54,8 @@ SearchPathWrapper(
 
     EX_TRY
     {
+#ifdef HOST_WINDOWS
         LongPathString Existingpath(LongPathString::Literal, lpPath);
-
         if (lpPath != NULL)
         {
             if (FAILED(LongFile::NormalizePath(Existingpath)))
@@ -258,6 +67,7 @@ SearchPathWrapper(
                 lpPath = Existingpath.GetUnicode();
             }
         }
+#endif // HOST_WINDOWS
 
         if (!getPath)
         {
@@ -474,9 +284,152 @@ DWORD WINAPI GetEnvironmentVariableWrapper(
     return ret;
 }
 
-
 #ifdef HOST_WINDOWS
 
+HMODULE
+LoadLibraryExWrapper(
+        LPCWSTR lpLibFileName,
+        HANDLE hFile,
+        DWORD dwFlags
+        )
+{
+    CONTRACTL
+    {
+        NOTHROW;
+    }
+    CONTRACTL_END;
+
+    HRESULT hr   = S_OK;
+    HMODULE ret = NULL;
+    DWORD lastError = 0;
+
+    EX_TRY
+    {
+        LongPathString path(LongPathString::Literal, lpLibFileName);
+
+        if (LongFile::IsPathNotFullyQualified(path) || SUCCEEDED(LongFile::NormalizePath(path)))
+        {
+            LongFile::NormalizeDirectorySeparators(path);
+
+            ret = LoadLibraryExW(path.GetUnicode(), hFile, dwFlags);
+        }
+
+        lastError = GetLastError();
+    }
+    EX_CATCH_HRESULT(hr);
+
+    if (hr != S_OK)
+    {
+        SetLastError(hr);
+    }
+    else if(ret == NULL)
+    {
+        SetLastError(lastError);
+    }
+
+    return ret;
+}
+
+HANDLE
+CreateFileWrapper(
+        _In_ LPCWSTR lpFileName,
+        _In_ DWORD dwDesiredAccess,
+        _In_ DWORD dwShareMode,
+        _In_opt_ LPSECURITY_ATTRIBUTES lpSecurityAttributes,
+        _In_ DWORD dwCreationDisposition,
+        _In_ DWORD dwFlagsAndAttributes,
+        _In_opt_ HANDLE hTemplateFile
+        )
+{
+    CONTRACTL
+    {
+        NOTHROW;
+    }
+    CONTRACTL_END;
+
+    HRESULT hr = S_OK;
+    DWORD lastError = 0;
+    HANDLE ret = INVALID_HANDLE_VALUE;
+
+    EX_TRY
+    {
+        LongPathString path(LongPathString::Literal, lpFileName);
+
+        if (SUCCEEDED(LongFile::NormalizePath(path)))
+        {
+            ret = CreateFileW(path.GetUnicode(),
+                    dwDesiredAccess,
+                    dwShareMode,
+                    lpSecurityAttributes,
+                    dwCreationDisposition,
+                    dwFlagsAndAttributes,
+                    hTemplateFile);
+
+        }
+
+        lastError = GetLastError();
+    }
+    EX_CATCH_HRESULT(hr);
+
+    if (hr != S_OK )
+    {
+        SetLastError(hr);
+    }
+    else if(ret == INVALID_HANDLE_VALUE)
+    {
+        SetLastError(lastError);
+    }
+
+    return ret;
+}
+
+BOOL
+GetFileAttributesExWrapper(
+        _In_ LPCWSTR lpFileName,
+        _In_ GET_FILEEX_INFO_LEVELS fInfoLevelId,
+        _Out_writes_bytes_(sizeof(WIN32_FILE_ATTRIBUTE_DATA)) LPVOID lpFileInformation
+        )
+{
+    CONTRACTL
+    {
+        NOTHROW;
+    }
+    CONTRACTL_END;
+
+    HRESULT hr = S_OK;
+    BOOL   ret = FALSE;
+    DWORD lastError = 0;
+
+    EX_TRY
+    {
+        LongPathString path(LongPathString::Literal, lpFileName);
+
+        if (SUCCEEDED(LongFile::NormalizePath(path)))
+        {
+            ret = GetFileAttributesExW(
+                    path.GetUnicode(),
+                    fInfoLevelId,
+                    lpFileInformation
+                    );
+
+        }
+
+        lastError = GetLastError();
+    }
+    EX_CATCH_HRESULT(hr);
+
+    if (hr != S_OK )
+    {
+        SetLastError(hr);
+    }
+    else if(ret == FALSE)
+    {
+        SetLastError(lastError);
+    }
+
+    return ret;
+}
+
 BOOL
 CopyFileExWrapper(
         _In_        LPCWSTR lpExistingFileName,
@@ -530,12 +483,10 @@ CopyFileExWrapper(
 
     return ret;
 }
-#endif // HOST_WINDOWS
 
 //Implementation of LongFile Helpers
 const WCHAR LongFile::DirectorySeparatorChar = W('\\');
 const WCHAR LongFile::AltDirectorySeparatorChar = W('/');
-#ifdef HOST_WINDOWS
 const WCHAR LongFile::VolumeSeparatorChar = W(':');
 const WCHAR* LongFile::ExtendedPrefix = W("\\\\?\\");
 const WCHAR* LongFile::DevicePathPrefix = W("\\\\.\\");
@@ -682,25 +633,10 @@ HRESULT LongFile::NormalizePath(SString & path)
 
     return S_OK;
 }
-#else
-BOOL LongFile::IsPathNotFullyQualified(const SString & path)
-{
-    return TRUE;
-}
-
-//Don't need to do anything For XPlat
-HRESULT LongFile::NormalizePath(SString & path)
-{
-    return S_OK;
-}
-#endif //HOST_WINDOWS
-
-BOOL LongFile::ContainsDirectorySeparator(SString & path)
-{
-    return path.Find(path.Begin(), DirectorySeparatorChar) || path.Find(path.Begin(), AltDirectorySeparatorChar);
-}
 
 BOOL LongFile::IsDirectorySeparator(WCHAR c)
 {
-    return c == DirectorySeparatorChar || c == AltDirectorySeparatorChar;
+    return c == DirectorySeparatorChar || c == AltDirectorySeparatorChar;;
 }
+
+#endif //HOST_WINDOWS
diff --git a/src/coreclr/utilcode/splitpath.cpp b/src/coreclr/utilcode/splitpath.cpp
index 949bf8b5dc5eb..0564990c20ff0 100644
--- a/src/coreclr/utilcode/splitpath.cpp
+++ b/src/coreclr/utilcode/splitpath.cpp
@@ -76,7 +76,6 @@ void    SplitPathInterior(
      *  relative path:
      *      top\next\last\  ; or
      *      top/next/last/
-     *  Mixed use of '/' and '\' within a path is also tolerated
      *  fname:
      *  0 to _MAX_FNAME-1 characters not including the '.' character
      *  ext:
@@ -108,7 +107,7 @@ void    SplitPathInterior(
      */
 
     for (last_slash = NULL, p = (WCHAR *)wszPath; *p; p++) {
-        if (*p == _T('/') || *p == _T('\\'))
+        if (*p == DIRECTORY_SEPARATOR_CHAR_W)
             /* point to one beyond for later copy */
             last_slash = p + 1;
         else if (*p == _T('.'))
diff --git a/src/coreclr/vm/clrex.cpp b/src/coreclr/vm/clrex.cpp
index a8440f3f927a8..2073bcaf3e391 100644
--- a/src/coreclr/vm/clrex.cpp
+++ b/src/coreclr/vm/clrex.cpp
@@ -1554,10 +1554,7 @@ void EEFileLoadException::SetFileName(const SString &fileName, BOOL removePath)
     {
         SString::CIterator i = fileName.End();
 
-        if (fileName.FindBack(i, W('\\')))
-            i++;
-
-        if (fileName.FindBack(i, W('/')))
+        if (fileName.FindBack(i, DIRECTORY_SEPARATOR_CHAR_W))
             i++;
 
         m_name.Set(fileName, i, fileName.End());
diff --git a/src/coreclr/vm/codeman.cpp b/src/coreclr/vm/codeman.cpp
index a81a2bd9f663f..0dc1e17680681 100644
--- a/src/coreclr/vm/codeman.cpp
+++ b/src/coreclr/vm/codeman.cpp
@@ -1940,8 +1940,10 @@ JIT_LOAD_DATA g_JitLoadData;
 //  load a JIT from the root of the drive.
 //
 //  The minimal set of characters that we must check for and exclude are:
-//     '\\' - (backslash)
+//  On all platforms:
 //     '/'  - (forward slash)
+//  On Windows:
+//     '\\' - (backslash)
 //     ':'  - (colon)
 //
 //  Returns false if we find any of these characters in 'pwzJitName'
@@ -1954,7 +1956,11 @@ static bool ValidateJitName(LPCWSTR pwzJitName)
     wchar_t curChar;
     do {
         curChar = *pCurChar;
-        if ((curChar == '\\') || (curChar == '/') || (curChar == ':'))
+        if (curChar == '/'
+#ifdef TARGET_WINDOWS
+            || (curChar == '\\') || (curChar == ':')
+#endif
+        )
         {
             //  Return false if we find any of these character in 'pwzJitName'
             return false;
diff --git a/src/coreclr/vm/eeconfig.cpp b/src/coreclr/vm/eeconfig.cpp
index 64df3d427f532..130bdd82f7bf7 100644
--- a/src/coreclr/vm/eeconfig.cpp
+++ b/src/coreclr/vm/eeconfig.cpp
@@ -388,7 +388,7 @@ HRESULT EEConfig::sync()
                 if (WszGetModuleFileName(NULL, wszFileName) != 0)
                 {
                     // just keep the name
-                    LPCWSTR pwszName = wcsrchr(wszFileName, W('\\'));
+                    LPCWSTR pwszName = wcsrchr(wszFileName, DIRECTORY_SEPARATOR_CHAR_W);
                     pwszName = (pwszName == NULL) ? wszFileName.GetUnicode() : (pwszName + 1);
 
                     if (SString::_wcsicmp(pwszName,pszGCStressExe) == 0)
diff --git a/src/coreclr/vm/gdbjit.cpp b/src/coreclr/vm/gdbjit.cpp
index bea3035299d9c..0f22e98aaf5a8 100644
--- a/src/coreclr/vm/gdbjit.cpp
+++ b/src/coreclr/vm/gdbjit.cpp
@@ -3610,7 +3610,7 @@ const char * NotifyGdb::SplitFilename(const char* path)
     const char *pSlash = nullptr;
     for (const char *p = path; *p != '\0'; p++)
     {
-        if (*p == '/' || *p == '\\')
+        if (*p == DIRECTORY_SEPARATOR_CHAR_A)
             pSlash = p;
     }
 
diff --git a/src/coreclr/vm/multicorejit.cpp b/src/coreclr/vm/multicorejit.cpp
index 3526ef15c7bb6..d52d71081f804 100644
--- a/src/coreclr/vm/multicorejit.cpp
+++ b/src/coreclr/vm/multicorejit.cpp
@@ -995,9 +995,9 @@ HRESULT MulticoreJitRecorder::StartProfile(const WCHAR * pRoot, const WCHAR * pF
         // Append separator if root does not end with one
         unsigned len = m_fullFileName.GetCount();
 
-        if ((len != 0) && (m_fullFileName[len - 1] != W('\\')))
+        if ((len != 0) && (m_fullFileName[len - 1] != DIRECTORY_SEPARATOR_CHAR_W))
         {
-            m_fullFileName.Append(W('\\'));
+            m_fullFileName.Append(DIRECTORY_SEPARATOR_CHAR_W);
         }
 
         m_fullFileName.Append(pFile);
diff --git a/src/coreclr/vm/peassembly.cpp b/src/coreclr/vm/peassembly.cpp
index 1f73b9122615b..0faee2e520c90 100644
--- a/src/coreclr/vm/peassembly.cpp
+++ b/src/coreclr/vm/peassembly.cpp
@@ -927,7 +927,7 @@ void PEAssembly::PathToUrl(SString &string)
     }
 #else
     // Unix doesn't have a distinction between a network or a local path
-    _ASSERTE( i[0] == W('\\') || i[0] == W('/'));
+    _ASSERTE(i[0] == W('/'));
     SString sss(SString::Literal, W("file://"));
     string.Insert(i, sss);
     string.Skip(i, sss);
@@ -960,33 +960,19 @@ void PEAssembly::UrlToPath(SString &string)
     if (string.MatchCaseInsensitive(i, sss2))
         string.Delete(i, 7);
 
+#if !defined(TARGET_UNIX)
     while (string.Find(i, W('/')))
     {
         string.Replace(i, W('\\'));
     }
+#endif
 
     RETURN;
 }
 
 BOOL PEAssembly::FindLastPathSeparator(const SString &path, SString::Iterator &i)
 {
-#ifdef TARGET_UNIX
-    SString::Iterator slash = i;
-    SString::Iterator backSlash = i;
-    BOOL foundSlash = path.FindBack(slash, '/');
-    BOOL foundBackSlash = path.FindBack(backSlash, '\\');
-    if (!foundSlash && !foundBackSlash)
-        return FALSE;
-    else if (foundSlash && !foundBackSlash)
-        i = slash;
-    else if (!foundSlash && foundBackSlash)
-        i = backSlash;
-    else
-        i = (backSlash > slash) ? backSlash : slash;
-    return TRUE;
-#else
-    return path.FindBack(i, '\\');
-#endif //TARGET_UNIX
+    return path.FindBack(i, DIRECTORY_SEPARATOR_CHAR_A);
 }
 
 // ------------------------------------------------------------
diff --git a/src/coreclr/vm/peimage.cpp b/src/coreclr/vm/peimage.cpp
index 0ef20ab146b0b..8d87ab168db86 100644
--- a/src/coreclr/vm/peimage.cpp
+++ b/src/coreclr/vm/peimage.cpp
@@ -170,7 +170,7 @@ CHECK PEImage::CheckCanonicalFullPath(const SString &path)
         MODE_ANY;
     }
     CONTRACT_CHECK_END;
-
+#ifdef TARGET_WINDOWS
     CCHECK_START
     {
         // This is not intended to be an exhaustive test, just to provide a sanity check
@@ -197,19 +197,19 @@ CHECK PEImage::CheckCanonicalFullPath(const SString &path)
         while (i != path.End())
         {
             // Check for multiple slashes
-            if(*i != '\\')
+            if(*i != DIRECTORY_SEPARATOR_CHAR_A)
             {
 
                 // Check for . or ..
                 SString sParentDir(SString::Ascii, "..");
                 SString sCurrentDir(SString::Ascii, ".");
                 if ((path.Skip(i, sParentDir) || path.Skip(i, sCurrentDir))
-                    && (path.Match(i, '\\')))
+                    && (path.Match(i, DIRECTORY_SEPARATOR_CHAR_A)))
                 {
                     CCHECK_FAIL("Illegal . or ..");
                 }
 
-                if (!path.Find(i, '\\'))
+                if (!path.Find(i, DIRECTORY_SEPARATOR_CHAR_A))
                     break;
             }
 
@@ -217,6 +217,7 @@ CHECK PEImage::CheckCanonicalFullPath(const SString &path)
         }
     }
     CCHECK_END;
+#endif // TARGET_WINDOWS
 
     CHECK_OK;
 }
diff --git a/src/coreclr/vm/peimage.inl b/src/coreclr/vm/peimage.inl
index 3fec6c1086e51..833d00ee230a7 100644
--- a/src/coreclr/vm/peimage.inl
+++ b/src/coreclr/vm/peimage.inl
@@ -78,7 +78,7 @@ inline void PEImage::SetModuleFileNameHintForDAC()
     {
         const WCHAR* pChar = pStartPath + nChars;
         nChars = 0;
-        while ((pChar >= pStartPath) && (*pChar != L'\\'))
+        while ((pChar >= pStartPath) && (*pChar != DIRECTORY_SEPARATOR_CHAR_W))
         {
             pChar--;
             nChars++;
diff --git a/src/coreclr/vm/stubgen.cpp b/src/coreclr/vm/stubgen.cpp
index 74f7428928dff..3528b0656964f 100644
--- a/src/coreclr/vm/stubgen.cpp
+++ b/src/coreclr/vm/stubgen.cpp
@@ -44,8 +44,8 @@ void DumpIL_RemoveFullPath(SString &strTokenFormatting)
     {
         SString::Iterator lastSlash = strTokenFormatting.End() - 1;
 
-        // Find the last '\\' in the string.
-        while ((lastSlash != leftBracket) && (*lastSlash != '\\'))
+        // Find the last directory separator character ('\\' on Windows, '/' on Unix) in the string.
+        while ((lastSlash != leftBracket) && (*lastSlash != DIRECTORY_SEPARATOR_CHAR_A))
         {
             --lastSlash;
         }
diff --git a/src/installer/tests/Microsoft.NET.HostModel.Tests/AppHost.Bundle.Tests/BundleExtractToSpecificPath.cs b/src/installer/tests/Microsoft.NET.HostModel.Tests/AppHost.Bundle.Tests/BundleExtractToSpecificPath.cs
index 8c3b8a4ee4460..36f5ec5adcfd1 100644
--- a/src/installer/tests/Microsoft.NET.HostModel.Tests/AppHost.Bundle.Tests/BundleExtractToSpecificPath.cs
+++ b/src/installer/tests/Microsoft.NET.HostModel.Tests/AppHost.Bundle.Tests/BundleExtractToSpecificPath.cs
@@ -79,6 +79,11 @@ private void Bundle_Extraction_To_Relative_Path_Succeeds(string relativePath, Bu
             if (relativePath == "foo/bar" && OperatingSystem.IsWindows())
                 return;
 
+            // Similarly on non-Windows OSes, we don't convert backslash directory separators
+            // to forward ones.
+            if (relativePath == "foo\\bar" && !OperatingSystem.IsWindows())
+                return;
+
             var fixture = sharedTestState.TestFixture.Copy();
             var bundler = BundleSelfContainedApp(fixture, out var singleFile, bundleOptions);
 
diff --git a/src/libraries/System.Runtime/tests/System/Type/TypeTests.cs b/src/libraries/System.Runtime/tests/System/Type/TypeTests.cs
index 03fc052ef4a9d..7a92fc1be38b1 100644
--- a/src/libraries/System.Runtime/tests/System/Type/TypeTests.cs
+++ b/src/libraries/System.Runtime/tests/System/Type/TypeTests.cs
@@ -852,7 +852,7 @@ public class ContextBoundClass : ContextBoundObject
         static string testtype = "System.Collections.Generic.Dictionary`2[[Program, Foo], [Program, Foo]]";
 
         private static Func<AssemblyName, Assembly> assemblyloader = (aName) => aName.Name == "TestLoadAssembly" ?
-                           Assembly.LoadFrom(@".\TestLoadAssembly.dll") :
+                           Assembly.LoadFrom(Path.Join(".", "TestLoadAssembly.dll")) :
                            null;
         private static Func<Assembly, string, bool, Type> typeloader = (assem, name, ignore) => assem == null ?
                              Type.GetType(name, false, ignore) :
diff --git a/src/tests/Loader/CollectibleAssemblies/ResolvedFromDifferentContext/ResolvedFromDifferentContext.cs b/src/tests/Loader/CollectibleAssemblies/ResolvedFromDifferentContext/ResolvedFromDifferentContext.cs
index 18f876d521d6a..c7469d09f66be 100644
--- a/src/tests/Loader/CollectibleAssemblies/ResolvedFromDifferentContext/ResolvedFromDifferentContext.cs
+++ b/src/tests/Loader/CollectibleAssemblies/ResolvedFromDifferentContext/ResolvedFromDifferentContext.cs
@@ -31,7 +31,7 @@ protected override Assembly Load(AssemblyName assemblyName)
         {
             AssemblyLoadContext alc1 = new AssemblyLoadContext("Dependencies", true);
             Console.WriteLine($"Loading TestInterface by alc {alc1} for {(IsCollectible ? "collectible" : "non-collectible")} alc {this}");
-            Assembly a = alc1.LoadFromAssemblyPath(Test.GetTestAssemblyPath(@"..\TestInterface\TestInterface.dll"));
+            Assembly a = alc1.LoadFromAssemblyPath(Test.GetTestAssemblyPath(Path.Join("..", "TestInterface", "TestInterface.dll")));
             interfaceAssemblyRef = new WeakReference(a);
             return a;
         }
@@ -56,7 +56,7 @@ private static Assembly LoadUsingResolvingEvent(bool collectibleParent)
         alc1 = new AssemblyLoadContext("Dependencies", true);
         AssemblyLoadContext alc2 = new AssemblyLoadContext("Test1", collectibleParent);
         alc2.Resolving += Alc2_Resolving;
-        Assembly assembly = alc2.LoadFromAssemblyPath(Test.GetTestAssemblyPath(@"..\TestClass\TestClass.dll"));
+        Assembly assembly = alc2.LoadFromAssemblyPath(Test.GetTestAssemblyPath(Path.Join("..", "TestClass", "TestClass.dll")));
 
         Type t = assembly.GetType("TestClass.Class");
         Console.WriteLine($"Type {t} obtained");
@@ -76,7 +76,7 @@ private static Assembly Alc2_Resolving(AssemblyLoadContext arg1, AssemblyName ar
         if (alc1 != null && arg2.Name == "TestInterface")
         {
             Console.WriteLine($"Loading TestInterface by alc {alc1} for {(arg1.IsCollectible ? "collectible" : "non-collectible")} alc {arg1}");
-            Assembly a = alc1.LoadFromAssemblyPath(Test.GetTestAssemblyPath(@"..\TestInterface\TestInterface.dll"));
+            Assembly a = alc1.LoadFromAssemblyPath(Test.GetTestAssemblyPath(Path.Join("..", "TestInterface", "TestInterface.dll")));
             interfaceAssemblyRef = new WeakReference(a);
             return a;
         }
@@ -88,7 +88,7 @@ private static Assembly Alc2_Resolving(AssemblyLoadContext arg1, AssemblyName ar
     private static Assembly LoadUsingLoadOverride(bool collectibleParent)
     {
         TestAssemblyLoadContext alc2 = new TestAssemblyLoadContext("Test2", collectibleParent);
-        Assembly assembly = alc2.LoadFromAssemblyPath(Test.GetTestAssemblyPath(@"..\TestClass\TestClass.dll"));
+        Assembly assembly = alc2.LoadFromAssemblyPath(Test.GetTestAssemblyPath(Path.Join("..", "TestClass", "TestClass.dll")));
 
         Type t = assembly.GetType("TestClass.Class");