diff --git a/backends/platform/dc/dc.h b/backends/platform/dc/dc.h
index 8a122ebb278..e87a0a8c904 100644
--- a/backends/platform/dc/dc.h
+++ b/backends/platform/dc/dc.h
@@ -86,7 +86,7 @@ class OSystem_Dreamcast : private DCHardware, public BaseBackend, public Filesys
   Graphics::PixelFormat getScreenFormat() const;
 
   // Returns a list of all pixel formats supported by the backend.
-  Common::List<Graphics::PixelFormat> getSupportedFormats();
+  Common::List<Graphics::PixelFormat> getSupportedFormats() const;
 
   // Set the size of the video bitmap.
   // Typically, 320x200
diff --git a/backends/platform/dc/display.cpp b/backends/platform/dc/display.cpp
index 35fc94b3cca..53dbff333d6 100644
--- a/backends/platform/dc/display.cpp
+++ b/backends/platform/dc/display.cpp
@@ -198,7 +198,7 @@ Graphics::PixelFormat OSystem_Dreamcast::getScreenFormat() const
   return screenFormats[_screenFormat];
 }
 
-Common::List<Graphics::PixelFormat> OSystem_Dreamcast::getSupportedFormats()
+Common::List<Graphics::PixelFormat> OSystem_Dreamcast::getSupportedFormats() const
 {
   Common::List<Graphics::PixelFormat> list;
   unsigned i;
diff --git a/backends/platform/psp/display_manager.cpp b/backends/platform/psp/display_manager.cpp
index 15e0188ebfb..a9f33f60918 100644
--- a/backends/platform/psp/display_manager.cpp
+++ b/backends/platform/psp/display_manager.cpp
@@ -379,7 +379,7 @@ inline bool DisplayManager::isTimeToUpdate() {
 	return true;
 }
 
-Common::List<Graphics::PixelFormat> DisplayManager::getSupportedPixelFormats() {
+Common::List<Graphics::PixelFormat> DisplayManager::getSupportedPixelFormats() const {
 	Common::List<Graphics::PixelFormat> list;
 
 	// In order of preference
diff --git a/backends/platform/psp/display_manager.h b/backends/platform/psp/display_manager.h
index bceb85703db..dbbdf2022ce 100644
--- a/backends/platform/psp/display_manager.h
+++ b/backends/platform/psp/display_manager.h
@@ -83,12 +83,12 @@ public:
 	void setSizeAndPixelFormat(uint width, uint height, const Graphics::PixelFormat *format);
 
 	// Getters
-	float getScaleX() { return _displayParams.scaleX; }
-	float getScaleY() { return _displayParams.scaleY; }
-	uint32 getOutputWidth() { return _displayParams.screenOutput.width; }
-	uint32 getOutputHeight() { return _displayParams.screenOutput.height; }
-	uint32 getOutputBitsPerPixel() { return _displayParams.outputBitsPerPixel; }
-	Common::List<Graphics::PixelFormat> getSupportedPixelFormats();
+	float getScaleX() const { return _displayParams.scaleX; }
+	float getScaleY() const { return _displayParams.scaleY; }
+	uint32 getOutputWidth() const { return _displayParams.screenOutput.width; }
+	uint32 getOutputHeight() const { return _displayParams.screenOutput.height; }
+	uint32 getOutputBitsPerPixel() const { return _displayParams.outputBitsPerPixel; }
+	Common::List<Graphics::PixelFormat> getSupportedPixelFormats() const;
 
 private:
 	struct GlobalDisplayParams {
diff --git a/backends/platform/psp/osys_psp.cpp b/backends/platform/psp/osys_psp.cpp
index b0fb9712307..580e4f1cfd0 100644
--- a/backends/platform/psp/osys_psp.cpp
+++ b/backends/platform/psp/osys_psp.cpp
@@ -148,7 +148,7 @@ Graphics::PixelFormat OSystem_PSP::getScreenFormat() const {
 	return _screen.getScummvmPixelFormat();
 }
 
-Common::List<Graphics::PixelFormat> OSystem_PSP::getSupportedFormats() {
+Common::List<Graphics::PixelFormat> OSystem_PSP::getSupportedFormats() const {
 	return _displayManager.getSupportedPixelFormats();
 }
 
diff --git a/backends/platform/psp/osys_psp.h b/backends/platform/psp/osys_psp.h
index d8ec8fe824e..56a64ccb806 100644
--- a/backends/platform/psp/osys_psp.h
+++ b/backends/platform/psp/osys_psp.h
@@ -87,7 +87,7 @@ public:
 	int getGraphicsMode() const;
 #ifdef USE_RGB_COLOR
 	virtual Graphics::PixelFormat getScreenFormat() const;
-	virtual Common::List<Graphics::PixelFormat> getSupportedFormats();
+	virtual Common::List<Graphics::PixelFormat> getSupportedFormats() const;
 #endif
 
 	// Screen size
diff --git a/backends/platform/sdl/graphics.cpp b/backends/platform/sdl/graphics.cpp
index 82670cfcb79..83a256f568f 100644
--- a/backends/platform/sdl/graphics.cpp
+++ b/backends/platform/sdl/graphics.cpp
@@ -243,7 +243,7 @@ const Graphics::PixelFormat BGRList[] = {
 };
 
 // TODO: prioritize matching alpha masks
-Common::List<Graphics::PixelFormat> OSystem_SDL::getSupportedFormats() {
+Common::List<Graphics::PixelFormat> OSystem_SDL::getSupportedFormats() const {
 	static Common::List<Graphics::PixelFormat> list;
 	static bool inited = false;
 
diff --git a/backends/platform/sdl/sdl.h b/backends/platform/sdl/sdl.h
index 341a59c8cfd..480e0af41b5 100644
--- a/backends/platform/sdl/sdl.h
+++ b/backends/platform/sdl/sdl.h
@@ -98,7 +98,7 @@ public:
 	virtual Graphics::PixelFormat getScreenFormat() const { return _screenFormat; }
 
 	// Highest supported
-	virtual Common::List<Graphics::PixelFormat> getSupportedFormats();
+	virtual Common::List<Graphics::PixelFormat> getSupportedFormats() const;
 #endif
 
 	// Set the size and format of the video bitmap.
diff --git a/backends/platform/wii/osystem.h b/backends/platform/wii/osystem.h
index d277aa38b1a..8180d5727f3 100644
--- a/backends/platform/wii/osystem.h
+++ b/backends/platform/wii/osystem.h
@@ -156,7 +156,7 @@ public:
 	virtual bool setGraphicsMode(int mode);
 #ifdef USE_RGB_COLOR
 	virtual Graphics::PixelFormat getScreenFormat() const;
-	virtual Common::List<Graphics::PixelFormat> getSupportedFormats();
+	virtual Common::List<Graphics::PixelFormat> getSupportedFormats() const;
 #endif
 	virtual int getGraphicsMode() const;
 	virtual void initSize(uint width, uint height,
diff --git a/backends/platform/wii/osystem_gfx.cpp b/backends/platform/wii/osystem_gfx.cpp
index 3d4e75883b6..19190048a0e 100644
--- a/backends/platform/wii/osystem_gfx.cpp
+++ b/backends/platform/wii/osystem_gfx.cpp
@@ -209,7 +209,7 @@ Graphics::PixelFormat OSystem_Wii::getScreenFormat() const {
 	return _pfGame;
 }
 
-Common::List<Graphics::PixelFormat> OSystem_Wii::getSupportedFormats() {
+Common::List<Graphics::PixelFormat> OSystem_Wii::getSupportedFormats() const {
 	Common::List<Graphics::PixelFormat> res;
 	res.push_back(_pfRGB565);
 	res.push_back(Graphics::PixelFormat::createFormatCLUT8());
diff --git a/common/system.h b/common/system.h
index 60cea49f873..a09912b3a71 100644
--- a/common/system.h
+++ b/common/system.h
@@ -383,7 +383,7 @@ public:
 	 * @note Backends supporting RGB color should accept game data in RGB color
 	 *       order, even if hardware uses BGR or some other color order.
 	 */
-	virtual Common::List<Graphics::PixelFormat> getSupportedFormats() = 0;
+	virtual Common::List<Graphics::PixelFormat> getSupportedFormats() const = 0;
 #else
 	inline Graphics::PixelFormat getScreenFormat() const {
 		return Graphics::PixelFormat::createFormatCLUT8();