diff --git a/src/gfx_func.h b/src/gfx_func.h
--- a/src/gfx_func.h
+++ b/src/gfx_func.h
@@ -121,6 +121,7 @@ void DrawDirtyBlocks();
 void AddDirtyBlock(int left, int top, int right, int bottom);
 void MarkWholeScreenDirty();
 
+bool CopyPalette(Palette &local_palette, bool force_copy = false);
 void GfxInitPalettes();
 void CheckBlitter();