diff --git a/src/gl/compatibility/gl_20.cpp b/src/gl/compatibility/gl_20.cpp
index d0de0589c..7e8ad093a 100644
--- a/src/gl/compatibility/gl_20.cpp
+++ b/src/gl/compatibility/gl_20.cpp
@@ -53,6 +53,54 @@
 #include "gl/renderer/gl_renderstate.h"
 #include "gl/scene/gl_drawinfo.h"
 
+
+//==========================================================================
+//
+// Do some tinkering with the menus so that certain options only appear
+// when they are actually valid.
+//
+//==========================================================================
+
+void gl_PatchMenu()
+{
+	if (gl.compatibility == CMPT_GL2)
+	{
+		// Radial fog and Doom lighting are not available in SM < 4 cards
+		// The way they are implemented does not work well on older hardware.
+
+		FOptionValues **opt = OptionValues.CheckKey("LightingModes");
+		if (opt != NULL) 
+		{
+			for(int i = (*opt)->mValues.Size()-1; i>=0; i--)
+			{
+				// Delete 'Doom' lighting mode
+				if ((*opt)->mValues[i].Value == 2.0 || (*opt)->mValues[i].Value == 8.0)
+				{
+					(*opt)->mValues.Delete(i);
+				}
+			}
+		}
+
+		opt = OptionValues.CheckKey("FogMode");
+		if (opt != NULL) 
+		{
+			for(int i = (*opt)->mValues.Size()-1; i>=0; i--)
+			{
+				// Delete 'Radial' fog mode
+				if ((*opt)->mValues[i].Value == 2.0)
+				{
+					(*opt)->mValues.Delete(i);
+				}
+			}
+		}
+
+		// disable features that don't work without shaders.
+		if (gl_lightmode == 2 || gl_lightmode == 8) gl_lightmode = 3;
+		if (gl_fogmode == 2) gl_fogmode = 1;
+	}
+}
+
+
 //==========================================================================
 //
 //
@@ -499,4 +547,5 @@ void FGLRenderer::RenderMultipassStuff()
 		gl_drawinfo->dldrawlists[GLLDL_FLATS_FOGMASKED].DrawFlats(GLPASS_LIGHTTEX_ADDITIVE);
 	}
 	else gl_lights = false;
-}
\ No newline at end of file
+}
+
diff --git a/src/gl/models/gl_models.cpp b/src/gl/models/gl_models.cpp
index 4db7a5f66..dc937ea40 100644
--- a/src/gl/models/gl_models.cpp
+++ b/src/gl/models/gl_models.cpp
@@ -325,8 +325,8 @@ FTexture * LoadSkin(const char * path, const char * fn)
 
 static int ModelFrameHash(FSpriteModelFrame * smf)
 {
-	const DWORD *table = GetCRCTable ();
-	DWORD hash = 0xffffffff;
+	const uint32_t *table = GetCRCTable ();
+	uint32_t hash = 0xffffffff;
 
 	const char * s = (const char *)(&smf->type);	// this uses type, sprite and frame for hashing
 	const char * se= (const char *)(&smf->hashnext);
diff --git a/src/gl/models/gl_models_md3.cpp b/src/gl/models/gl_models_md3.cpp
index 7e8a4845e..024f8ac81 100644
--- a/src/gl/models/gl_models_md3.cpp
+++ b/src/gl/models/gl_models_md3.cpp
@@ -77,45 +77,45 @@ static void UnpackVector(unsigned short packed, float & nx, float & ny, float &
 #pragma pack(4)
 struct md3_header_t
 {
-	DWORD Magic;
-	DWORD Version;
+	uint32_t Magic;
+	uint32_t Version;
 	char Name[MAX_QPATH];
-	DWORD Flags;
-	DWORD Num_Frames;
-	DWORD Num_Tags;
-	DWORD Num_Surfaces;
-	DWORD Num_Skins;
-	DWORD Ofs_Frames;
-	DWORD Ofs_Tags;
-	DWORD Ofs_Surfaces;
-	DWORD Ofs_Eof;
+	uint32_t Flags;
+	uint32_t Num_Frames;
+	uint32_t Num_Tags;
+	uint32_t Num_Surfaces;
+	uint32_t Num_Skins;
+	uint32_t Ofs_Frames;
+	uint32_t Ofs_Tags;
+	uint32_t Ofs_Surfaces;
+	uint32_t Ofs_Eof;
 };
 
 struct md3_surface_t
 {
-	DWORD Magic;
+	uint32_t Magic;
 	char Name[MAX_QPATH];
-	DWORD Flags;
-	DWORD Num_Frames;
-	DWORD Num_Shaders;
-	DWORD Num_Verts;
-	DWORD Num_Triangles;
-	DWORD Ofs_Triangles;
-	DWORD Ofs_Shaders;
-	DWORD Ofs_Texcoord;
-	DWORD Ofs_XYZNormal;
-	DWORD Ofs_End;
+	uint32_t Flags;
+	uint32_t Num_Frames;
+	uint32_t Num_Shaders;
+	uint32_t Num_Verts;
+	uint32_t Num_Triangles;
+	uint32_t Ofs_Triangles;
+	uint32_t Ofs_Shaders;
+	uint32_t Ofs_Texcoord;
+	uint32_t Ofs_XYZNormal;
+	uint32_t Ofs_End;
 };
 
 struct md3_triangle_t
 {
-	DWORD vt_index[3];
+	uint32_t vt_index[3];
 };
 
 struct md3_shader_t
 {
 	char Name[MAX_QPATH];
-	DWORD index;
+	uint32_t index;
 };
 
 struct md3_texcoord_t
diff --git a/src/gl/system/gl_interface.cpp b/src/gl/system/gl_interface.cpp
index 19f6134c3..e6e802e5c 100644
--- a/src/gl/system/gl_interface.cpp
+++ b/src/gl/system/gl_interface.cpp
@@ -47,12 +47,10 @@
 #include "gl/system/gl_interface.h"
 #include "gl/system/gl_cvars.h"
 
+void gl_PatchMenu();
 static TArray<FString>  m_Extensions;
-
 RenderContext gl;
 
-int occlusion_type=0;
-
 //==========================================================================
 //
 // 
@@ -273,6 +271,7 @@ void gl_LoadExtensions()
 	FUDGE_FUNC(glDeleteRenderbuffers, EXT);
 	FUDGE_FUNC(glRenderbufferStorage, EXT);
 	FUDGE_FUNC(glBindRenderbuffer, EXT);
+	gl_PatchMenu();
 }
 
 //==========================================================================