diff --git a/src/video/SDL_sysvideo.h b/src/video/SDL_sysvideo.h
index 3e14224c1..e0c54ba43 100644
--- a/src/video/SDL_sysvideo.h
+++ b/src/video/SDL_sysvideo.h
@@ -81,6 +81,7 @@ struct SDL_Window
     SDL_DisplayMode fullscreen_mode;
     
     SDL_Surface *surface;
+    SDL_bool surface_valid;
 
     SDL_WindowShaper *shaper;