diff --git a/apps/opencs/view/render/overlaymask.hpp b/apps/opencs/view/render/overlaymask.hpp
index 3a006b1d9..ec050cac4 100644
--- a/apps/opencs/view/render/overlaymask.hpp
+++ b/apps/opencs/view/render/overlaymask.hpp
@@ -35,7 +35,7 @@ namespace CSVRender
 
     protected:
 
-        virtual void preViewportUpdate(const Ogre::RenderTargetViewportEvent &event) override;
+        virtual void preViewportUpdate(const Ogre::RenderTargetViewportEvent &event);
     };
 }