diff --git a/dlls/opengl32/Makefile.in b/dlls/opengl32/Makefile.in
index 4df6bce..0aa1e91 100644
--- a/dlls/opengl32/Makefile.in
+++ b/dlls/opengl32/Makefile.in
@@ -1,3 +1,4 @@
+EXTRADEFS = -D_GDI32_
 MODULE    = opengl32.dll
 IMPORTLIB = opengl32
 IMPORTS   = user32 gdi32 advapi32