diff --git a/CMakeLists.txt b/CMakeLists.txt
index 52685cfbfe90..9685e2b12d0e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -66,7 +66,7 @@ elseif (MSVC)
     endif ()
     if (MSVC_VERSION GREATER 1914)
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /experimental:external /external:W2")
-		set(CMAKE_INCLUDE_SYSTEM_FLAG_CXX "/external:I ")
+        set(CMAKE_INCLUDE_SYSTEM_FLAG_CXX "/external:I ")
     endif ()
     # exporting symbols for shared libraries needs to enabled explicitly
     set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
@@ -142,6 +142,7 @@ endif (APPLE)
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" AND WIN32)
     option(USE_MINGW_64BITS "Use 64 bits libraries for the compilation with MinGW" true)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DWIN32 -D_WIN32_WINNT=0x0501")
+    set(MINGW32 1)
 endif ()
 
 # Check if libraries have to be found, depending on SUMO_LIBRARIES
diff --git a/src/config.h.cmake b/src/config.h.cmake
index ce10faafc9c3..6ca79a2ba868 100644
--- a/src/config.h.cmake
+++ b/src/config.h.cmake
@@ -1,4 +1,4 @@
-/* Check if we're using Microsoft Visual Studio */
+/* Macros for Microsoft Visual Studio */
 #ifdef _MSC_VER
 
     /* Disable "decorated name length exceeded, name was truncated" warnings. */
@@ -29,11 +29,14 @@
     #define FOX_CONSTRUCTOR(classname) __pragma(warning(suppress: 26495)) \
     classname() {}
 
-/* GNU Compiler */
+/* Macros for GNU Compiler */
 #else
 
+    /* defined if we're using MINGW32 */
+    #cmakedefine MINGW32
+
     /* Windows (MinGW32) */
-    #ifdef __MINGW32__
+    #ifdef MINGW32
 
         /* Define WIN32 */
         #ifndef WIN32
@@ -42,8 +45,8 @@
 
         /* Define for dynamic Fox linkage */
         #define FOXDLL 1
-		
-		/* Define default constructor for FOX moduls (MinGW32) */
+
+        /* Define default constructor for FOX moduls (MinGW32) */
         #define FOX_CONSTRUCTOR(classname) classname() {}
 
     /* Linux and OS */