1 files changed, 2 insertions, 0 deletions
diff --git a/src/mgl.h b/src/mgl.h
index 6f10078a0..f1686a2ba 100644
--- a/src/mgl.h
+++ b/src/mgl.h
@@ -126,6 +126,8 @@ defNameE(glDebugMessageCallback);
 typedef const char* (APIENTRY * wglGetExtensionsString_t) (HDC hdc);
 
 defNameE(wglGetExtensionsString);
+#else
+#define CALLBACK
 #endif
 
 #endif