diff --git a/neo/renderer/RenderSystem_init.cpp b/neo/renderer/RenderSystem_init.cpp
index 13b908bc..01330c5e 100644
--- a/neo/renderer/RenderSystem_init.cpp
+++ b/neo/renderer/RenderSystem_init.cpp
@@ -626,7 +626,7 @@ static void R_CheckPortableExtensions()
 		
 		if( r_debugContext.GetInteger() >= 1 )
 		{
-			qglDebugMessageCallbackARB( DebugCallback, NULL );
+			qglDebugMessageCallbackARB( (GLDEBUGPROCARB)DebugCallback, NULL );
 		}
 		if( r_debugContext.GetInteger() >= 2 )
 		{