diff --git a/Makefile b/Makefile
index 6085890..24ec562 100644
--- a/Makefile
+++ b/Makefile
@@ -242,7 +242,7 @@ else
 	SHARED := -shared -static-libgcc -static-libstdc++ -Wl,-no-undefined -Wl,-version-script=link.T
 	LIBS += -lshlwapi
 	HAVE_WIN32_MSX_MANAGER = 1
-
+	PLATFORM_DEFINES := -D__WIN32__
 endif
 
 CORE_DIR  := .
diff --git a/atari800/src/devices.c b/atari800/src/devices.c
index 925efdb..3d79a82 100644
--- a/atari800/src/devices.c
+++ b/atari800/src/devices.c
@@ -435,6 +435,9 @@ static int Devices_MakeDirectory(const char *filename)
 
 static int Devices_MakeDirectory(const char *filename)
 {
+#ifdef __WIN32__
+#define MKDIR_TAKES_ONE_ARG 1
+#endif
 	return mkdir(filename
 #ifndef MKDIR_TAKES_ONE_ARG
 		, 0777