diff --git a/engines/grim/gfx_base.h b/engines/grim/gfx_base.h
index cf813ad8c95..ecc5297a2ba 100644
--- a/engines/grim/gfx_base.h
+++ b/engines/grim/gfx_base.h
@@ -79,7 +79,7 @@ public:
 	 * @param screenH       the height of the context
 	 * @param fullscreen    true if fullscreen is desired, false otherwise.
 	 */
-	virtual byte *setupScreen(int screenW, int screenH, bool fullscreen) = 0;
+	virtual void setupScreen(int screenW, int screenH, bool fullscreen) = 0;
 
 	/**
 	 * Query whether the current context is hardware-accelerated
diff --git a/engines/grim/gfx_opengl.cpp b/engines/grim/gfx_opengl.cpp
index a65fda48cac..f41ab1b68f0 100644
--- a/engines/grim/gfx_opengl.cpp
+++ b/engines/grim/gfx_opengl.cpp
@@ -129,7 +129,7 @@ GfxOpenGL::~GfxOpenGL() {
 	}
 }
 
-byte *GfxOpenGL::setupScreen(int screenW, int screenH, bool fullscreen) {
+void GfxOpenGL::setupScreen(int screenW, int screenH, bool fullscreen) {
 	_screenWidth = screenW;
 	_screenHeight = screenH;
 	_scaleW = _screenWidth / (float)_gameWidth;
@@ -159,8 +159,6 @@ byte *GfxOpenGL::setupScreen(int screenW, int screenH, bool fullscreen) {
 
 	initExtensions();
 	glGetIntegerv(GL_MAX_LIGHTS, &_maxLights);
-
-	return nullptr;
 }
 
 void GfxOpenGL::initExtensions() {
diff --git a/engines/grim/gfx_opengl.h b/engines/grim/gfx_opengl.h
index fc5c54ae127..4cb789a4fa5 100644
--- a/engines/grim/gfx_opengl.h
+++ b/engines/grim/gfx_opengl.h
@@ -47,7 +47,7 @@ public:
 	GfxOpenGL();
 	virtual ~GfxOpenGL();
 
-	byte *setupScreen(int screenW, int screenH, bool fullscreen) override;
+	void setupScreen(int screenW, int screenH, bool fullscreen) override;
 
 	const char *getVideoDeviceName() override;
 
diff --git a/engines/grim/gfx_opengl_shaders.cpp b/engines/grim/gfx_opengl_shaders.cpp
index 7e14316de33..70e644d2b07 100644
--- a/engines/grim/gfx_opengl_shaders.cpp
+++ b/engines/grim/gfx_opengl_shaders.cpp
@@ -406,7 +406,7 @@ void GfxOpenGLS::setupShaders() {
 	}
 }
 
-byte *GfxOpenGLS::setupScreen(int screenW, int screenH, bool fullscreen) {
+void GfxOpenGLS::setupScreen(int screenW, int screenH, bool fullscreen) {
 	_screenWidth = screenW;
 	_screenHeight = screenH;
 	_scaleW = _screenWidth / (float)_gameWidth;
@@ -430,7 +430,6 @@ byte *GfxOpenGLS::setupScreen(int screenW, int screenH, bool fullscreen) {
 		// color map and the following are using textures.
 		glDepthFunc(GL_LEQUAL);
 	}
-	return NULL;
 }
 
 void GfxOpenGLS::setupCameraFrustum(float fov, float nclip, float fclip) {
diff --git a/engines/grim/gfx_opengl_shaders.h b/engines/grim/gfx_opengl_shaders.h
index af8a082f45b..35f832c3f16 100644
--- a/engines/grim/gfx_opengl_shaders.h
+++ b/engines/grim/gfx_opengl_shaders.h
@@ -43,7 +43,7 @@ public:
 	 * @param screenH		the height of the context
 	 * @param fullscreen	true if fullscreen is desired, false otherwise.
 	 */
-	virtual byte *setupScreen(int screenW, int screenH, bool fullscreen) override;
+	virtual void setupScreen(int screenW, int screenH, bool fullscreen) override;
 
 	/**
 	 * Query whether the current context is hardware-accelerated
diff --git a/engines/grim/gfx_tinygl.cpp b/engines/grim/gfx_tinygl.cpp
index f61105cca8f..13bd6430a74 100644
--- a/engines/grim/gfx_tinygl.cpp
+++ b/engines/grim/gfx_tinygl.cpp
@@ -77,9 +77,8 @@ GfxTinyGL::~GfxTinyGL() {
 	}
 }
 
-byte *GfxTinyGL::setupScreen(int screenW, int screenH, bool fullscreen) {
+void GfxTinyGL::setupScreen(int screenW, int screenH, bool fullscreen) {
 	Graphics::PixelBuffer buf = g_system->getScreenPixelBuffer();
-	byte *buffer = buf.getRawBuffer();
 
 	_screenWidth = screenW;
 	_screenHeight = screenH;
@@ -103,8 +102,6 @@ byte *GfxTinyGL::setupScreen(int screenW, int screenH, bool fullscreen) {
 	tglLightModelfv(TGL_LIGHT_MODEL_AMBIENT, ambientSource);
 	TGLfloat diffuseReflectance[] = { 1.0f, 1.0f, 1.0f, 1.0f };
 	tglMaterialfv(TGL_FRONT, TGL_DIFFUSE, diffuseReflectance);
-
-	return buffer;
 }
 
 const char *GfxTinyGL::getVideoDeviceName() {
diff --git a/engines/grim/gfx_tinygl.h b/engines/grim/gfx_tinygl.h
index b7b03c8c577..0e470d1ce7a 100644
--- a/engines/grim/gfx_tinygl.h
+++ b/engines/grim/gfx_tinygl.h
@@ -39,7 +39,7 @@ public:
 	GfxTinyGL();
 	virtual ~GfxTinyGL();
 
-	byte *setupScreen(int screenW, int screenH, bool fullscreen) override;
+	void setupScreen(int screenW, int screenH, bool fullscreen) override;
 
 	const char *getVideoDeviceName() override;