diff --git a/test/lit.cfg b/test/lit.cfg
index 35d6ac55029a7..1ef32985a4b9d 100644
--- a/test/lit.cfg
+++ b/test/lit.cfg
@@ -351,6 +351,7 @@ config.gyb = make_path(config.swift_utils, 'gyb.py')
 config.rth = make_path(config.swift_utils, 'rth') # Resilience test helper
 config.scale_test = make_path(config.swift_utils, 'scale-test')
 config.PathSanitizingFileCheck = make_path(config.swift_utils, 'PathSanitizingFileCheck')
+config.swift_bin_dir = make_path(config.swift, '..', '..', 'bin')
 config.swift_lib_dir = make_path(config.swift, '..', '..', 'lib')
 config.round_trip_syntax_test = make_path(config.swift_utils, 'round-trip-syntax-test')
 config.refactor_check_compiles = make_path(config.swift_utils, 'refactor-check-compiles.py')
diff --git a/utils/build-windows-toolchain.bat b/utils/build-windows-toolchain.bat
index 77eb0d8e9454e..5a2258750bfc1 100644
--- a/utils/build-windows-toolchain.bat
+++ b/utils/build-windows-toolchain.bat
@@ -18,7 +18,10 @@ set ProductTag=
 :: Identify the SourceRoot
 :: Normalize the SourceRoot to make it easier to read the output.
 cd %~dp0\..\..
-set SourceRoot=%CD%
+subst S: /d
+subst S: . || (exit /b)
+set SourceRoot=S:
+cd /d %SourceRoot%
 
 :: Identify the BuildRoot
 set BuildRoot=%SourceRoot%\build
@@ -54,6 +57,8 @@ del /f /q "%UniversalCRTSdkDir%\Include\%UCRTVersion%\um\module.modulemap"
 del /f /q "%VCToolsInstallDir%\include\module.modulemap"
 del /f /q "%VCToolsInstallDir%\include\vcruntime.apinotes"
 
+call :FetchWiX || (exit /b)
+call :FetchX64Toolchain || (exit /b)
 call :CloneDependencies || (exit /b)
 call :CloneRepositories || (exit /b)
 
@@ -190,6 +195,33 @@ cmake ^
 cmake --build "%BuildRoot%\curl" || (exit /b)
 cmake --build "%BuildRoot%\curl" --target install || (exit /b)
 
+path %BuildRoot%\toolchains\5.9.0\PFiles64\Swift\runtime-development\usr\bin;%BuildRoot%\toolchains\5.9.0\Library\Developer\Toolchains\unknown-Asserts-development.xctoolchain\usr\bin;%Path%
+
+:: Build Swift Syntax
+cmake ^
+  -B "%BuildRoot%\99" ^
+
+  -D BUILD_SHARED_LIBS=YES ^
+  -D CMAKE_BUILD_TYPE=%CMAKE_BUILD_TYPE% ^
+  -D CMAKE_C_COMPILER=cl.exe ^
+  -D CMAKE_C_FLAGS="/GS- /Oy /Gw /Gy" ^
+  -D CMAKE_CXX_COMPILER=cl ^
+  -D CMAKE_CXX_FLAGS="/GS- /Oy /Gw /Gy" ^
+  -D CMAKE_MT=mt ^
+  -D CMAKE_Swift_COMPILER=%BuildRoot%/toolchains/5.9.0/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin/swiftc.exe ^
+  -D CMAKE_Swift_FLAGS="-sdk %BuildRoot%/toolchains/5.9.0/Library/Developer/Platforms/Windows.platform/Developer/SDKs/Windows.sdk" ^
+  -D CMAKE_EXE_LINKER_FLAGS="/INCREMENTAL:NO" ^
+  -D CMAKE_SHARED_LINKER_FLAGS="/INCREMENTAL:NO" ^
+  -D CMAKE_Swift_FLAGS_RELEASE="-O" ^
+  -D CMAKE_Swift_FLAGS_RELWITHDEBINFO="-O" ^
+
+  -D CMAKE_INSTALL_PREFIX="%InstallRoot%" ^
+
+  -G Ninja ^
+  -S %SourceRoot%\swift-syntax || (exit /b)
+cmake --build %BuildRoot%\99 || (exit /b)
+cmake --build %BuildRoot%\99 --target install || (exit /b)
+
 :: Build Toolchain
 cmake ^
   -B "%BuildRoot%\1" ^
@@ -207,11 +239,17 @@ cmake ^
 
   -D CMAKE_INSTALL_PREFIX="%InstallRoot%" ^
 
+  -D CMAKE_Swift_COMPILER="%BuildRoot%/toolchains/5.9.0/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin/swiftc.exe" ^
+  -D CMAKE_Swift_FLAGS="-sdk %BuildRoot%/toolchains/5.9.0/Library/Developer/Platforms/Windows.platform/Developer/SDKs/Windows.sdk" ^
+
   -D LLVM_DEFAULT_TARGET_TRIPLE=x86_64-unknown-windows-msvc ^
 
   -D PACKAGE_VENDOR="swift.org" ^
   -D CLANG_VENDOR="swift.org" ^
   -D CLANG_VENDOR_UTI="org.swift" ^
+  -D LLDB_PYTHON_EXE_RELATIVE_PATH=python.exe ^
+  -D LLDB_PYTHON_EXT_SUFFIX=.pyd ^
+  -D LLDB_PYTHON_RELATIVE_PATH=lib/site-packages ^
   -D LLVM_APPEND_VC_REV=NO ^
   -D LLVM_VERSION_SUFFIX="" ^
 
@@ -226,9 +264,11 @@ cmake ^
   -D LLVM_EXTERNAL_CMARK_SOURCE_DIR="%SourceRoot%\cmark" ^
   -D PYTHON_HOME=%PYTHON_HOME% ^
   -D PYTHON_EXECUTABLE=%PYTHON_HOME%\python.exe ^
+  -D SWIFT_PATH_TO_EARLYSWIFTSYNTAX_BUILD_DIR="%BuildRoot%\99" ^
   -D SWIFT_PATH_TO_LIBDISPATCH_SOURCE="%SourceRoot%\swift-corelibs-libdispatch" ^
   -D SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE="%SourceRoot%\swift-syntax" ^
   -D SWIFT_PATH_TO_STRING_PROCESSING_SOURCE=%SourceRoot%\swift-experimental-string-processing ^
+  -D SWIFT_PATH_TO_SWIFT_SDK="%BuildRoot%/toolchains/5.9.0/Library/Developer/Platforms/Windows.platform/Developer/SDKs/Windows.sdk" ^
 
   -G Ninja ^
   -S llvm-project\llvm || (exit /b)
@@ -815,6 +855,30 @@ git clone --quiet --no-tags --depth 1 --branch curl-7_77_0 https://github.com/cu
 goto :eof
 endlocal
 
+:FetchWiX
+setlocal enableextensions enabledelayedexpansion
+
+curl.exe -sL https://www.nuget.org/api/v2/package/wix/4.0.1 -o wix-4.0.1.zip
+md WiX-4.0.1 || exit (/b)
+cd WiX-4.0.1 || exit (/b)
+tar -xf ../wix-4.0.1.zip || exit (/b)
+
+goto :eof
+endlocal
+
+:FetchX64Toolchain
+setlocal enableextensions enabledelayedexpansion
+
+curl.exe -k -sOL "https://download.swift.org/swift-5.9-release/windows10/swift-5.9-RELEASE/swift-5.9-RELEASE-windows10.exe" || (exit /b)
+"WiX-4.0.1\tools\net6.0\any\wix.exe" burn extract swift-5.9-RELEASE-windows10.exe -o %BuildRoot%\toolchains || (exit /b)
+msiexec.exe /qn /a "%BuildRoot%\toolchains\a0" TARGETDIR="%BuildRoot%\toolchains\5.9.0\" || (exit /b)
+msiexec.exe /qn /a "%BuildRoot%\toolchains\a1" TARGETDIR="%BuildRoot%\toolchains\5.9.0\" || (exit /b)
+msiexec.exe /qn /a "%BuildRoot%\toolchains\a2" TARGETDIR="%BuildRoot%\toolchains\5.9.0\" || (exit /b)
+msiexec.exe /qn /a "%BuildRoot%\toolchains\a3" TARGETDIR="%BuildRoot%\toolchains\5.9.0\" || (exit /b)
+
+goto :eof
+endlocal
+
 :TestSwift
 setlocal enableextensions enabledelayedexpansion