diff --git a/src/blitter/32bpp_base.hpp b/src/blitter/32bpp_base.hpp
--- a/src/blitter/32bpp_base.hpp
+++ b/src/blitter/32bpp_base.hpp
@@ -20,19 +20,19 @@
 /** Base for all 32bpp blitters. */
 class Blitter_32bppBase : public Blitter {
 public:
-	/* virtual */ uint8 GetScreenDepth() { return 32; }
-	/* virtual */ void *MoveTo(void *video, int x, int y);
-	/* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
-	/* virtual */ void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash);
-	/* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
-	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
-	/* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height);
-	/* virtual */ void CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch);
-	/* virtual */ void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y);
-	/* virtual */ int BufferSize(int width, int height);
-	/* virtual */ void PaletteAnimate(const Palette &palette);
-	/* virtual */ Blitter::PaletteAnimation UsePaletteAnimation();
-	/* virtual */ int GetBytesPerPixel() { return 4; }
+	uint8 GetScreenDepth() override { return 32; }
+	void *MoveTo(void *video, int x, int y) override;
+	void SetPixel(void *video, int x, int y, uint8 colour) override;
+	void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash) override;
+	void DrawRect(void *video, int width, int height, uint8 colour) override;
+	void CopyFromBuffer(void *video, const void *src, int width, int height) override;
+	void CopyToBuffer(const void *video, void *dst, int width, int height) override;
+	void CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch) override;
+	void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y) override;
+	int BufferSize(int width, int height) override;
+	void PaletteAnimate(const Palette &palette) override;
+	Blitter::PaletteAnimation UsePaletteAnimation() override;
+	int GetBytesPerPixel() override { return 4; }
 
 	/**
 	 * Look up the colour in the current palette.