diff --git a/src/glu/sgi/include/gluos.h b/src/glu/sgi/include/gluos.h
index 802aa8402d4..ac0a7874cec 100644
--- a/src/glu/sgi/include/gluos.h
+++ b/src/glu/sgi/include/gluos.h
@@ -60,6 +60,10 @@
 #pragma comment(linker, "/OPT:NOWIN98")
 #endif
 
+#ifndef WINGDIAPI
+#define WINGDIAPI
+#endif
+
 #elif defined(__OS2__)
 
 #include <stdlib.h>
diff --git a/src/glu/sgi/libutil/mipmap.c b/src/glu/sgi/libutil/mipmap.c
index 415dfaa5411..c475c96a208 100644
--- a/src/glu/sgi/libutil/mipmap.c
+++ b/src/glu/sgi/libutil/mipmap.c
@@ -6631,7 +6631,7 @@ static TexImage3Dproc pTexImage3D = 0;
 #  include <dlfcn.h>
 #  include <sys/types.h>
 #else
-#  include <windows.h>
+  WINGDIAPI PROC  WINAPI wglGetProcAddress(LPCSTR);
 #endif
 
 static void gluTexImage3D( GLenum target, GLint level,