diff --git a/gfx.mk b/gfx.mk
index 777934b9..1644176d 100644
--- a/gfx.mk
+++ b/gfx.mk
@@ -41,6 +41,12 @@ endif
 ifeq ($(OPT_OS),win32)
 	GFXDEFS += GFX_USE_OS_WIN32=TRUE
 endif
+ifeq ($(OPT_OS),win32.chibios)
+	GFXDEFS += GFX_USE_OS_CHIBIOS=TRUE
+endif
+ifeq ($(OPT_OS),win32.raw32)
+	GFXDEFS += GFX_USE_OS_RAW32=TRUE
+endif
 ifeq ($(OPT_OS),linux)
 	GFXDEFS += GFX_USE_OS_LINUX=TRUE
 endif
diff --git a/tools/gmake_scripts/os_win32.raw32.mk b/tools/gmake_scripts/os_win32.raw32.mk
new file mode 100644
index 00000000..8a9cf78b
--- /dev/null
+++ b/tools/gmake_scripts/os_win32.raw32.mk
@@ -0,0 +1,15 @@
+#
+# This file is subject to the terms of the GFX License. If a copy of
+# the license was not distributed with this file, you can obtain one at:
+#
+#             http://ugfx.org/license.html
+#
+
+# See readme.txt for the make API
+
+# Requirements:
+#
+# NONE
+#
+
+include $(GFXLIB)/tools/gmake_scripts/os_win32.mk