diff --git a/src/blitter/8bpp_debug.hpp b/src/blitter/8bpp_debug.hpp
--- a/src/blitter/8bpp_debug.hpp
+++ b/src/blitter/8bpp_debug.hpp
@@ -13,6 +13,8 @@ public:
 
 	/* virtual */ void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom);
 
+	/* virtual */ void DrawColorMappingRect(void *dst, int width, int height, int pal);
+
 	/* virtual */ Sprite *Encode(SpriteLoader::Sprite *sprite, Blitter::AllocatorProc *allocator);
 
 	/* virtual */ const char *GetRenderer() { return "8bpp"; }