diff --git a/libs/gfx/gl-loader-generator-config.json b/libs/gfx/gl-loader-generator-config.json
index d3068d2f..e92512dd 100644
--- a/libs/gfx/gl-loader-generator-config.json
+++ b/libs/gfx/gl-loader-generator-config.json
@@ -14,5 +14,6 @@
 	"undef": 4,
 	"strip": true,
 	"out_header": "gl.hpp",
-	"out_source": "gl.cpp"
+	"out_source": "gl.cpp",
+	"include": "<psemek/gfx/gl.hpp>"
 }
diff --git a/libs/gfx/include/psemek/gfx/gl.hpp b/libs/gfx/include/psemek/gfx/gl.hpp
index 2bce2d0d..6ee8f0bb 100644
--- a/libs/gfx/include/psemek/gfx/gl.hpp
+++ b/libs/gfx/include/psemek/gfx/gl.hpp
@@ -1,5 +1,32 @@
 #pragma once
 
+// Prevent inclusion of other OpenGL-related headers
+
+#if defined(__glew_h__) || defined(__GLEW_H__)
+#error Attempt to include auto-generated header after including glew.h
+#endif
+#if defined(__gl_h_) || defined(__GL_H__)
+#error Attempt to include auto-generated header after including gl.h
+#endif
+#if defined(__glext_h_) || defined(__GLEXT_H_)
+#error Attempt to include auto-generated header after including glext.h
+#endif
+#if defined(__gltypes_h_)
+#error Attempt to include auto-generated header after gltypes.h
+#endif
+#if defined(__gl_ATI_h_)
+#error Attempt to include auto-generated header after including glATI.h
+#endif
+
+#define __glew_h__
+#define __GLEW_H__
+#define __gl_h_
+#define __GL_H__
+#define __glext_h_
+#define __GLEXT_H_
+#define __gltypes_h_
+#define __gl_ATI_h_
+
 // Undefine some macros that may interfere with OpenGL constants
 
 #undef ZERO
diff --git a/libs/gfx/source/gl.cpp b/libs/gfx/source/gl.cpp
index 6caf0f5b..edc2f2b2 100644
--- a/libs/gfx/source/gl.cpp
+++ b/libs/gfx/source/gl.cpp
@@ -1,3 +1,5 @@
+#include <psemek/gfx/gl.hpp>
+
 
 #include <unordered_set>
 #include <string>
@@ -52,28 +54,28 @@ namespace gl
 		#pragma warning(disable: 4996)
 		#endif
 		
-		static int test_pointer(const PROC pTest)
+		static int test_pointer(const PROC p)
 		{
-			ptrdiff_t iTest;
-			if(!pTest) return 0;
-			iTest = (ptrdiff_t)pTest;
-			
-			if(iTest == 1 || iTest == 2 || iTest == 3 || iTest == -1) return 0;
-			
+			ptrdiff_t i;
+			if (!p) return 0;
+			i = (ptrdiff_t)p;
+		
+			if(i == 1 || i == 2 || i == 3 || i == -1) return 0;
+		
 			return 1;
 		}
 		
 		static void * get_proc_address(const char *name)
 		{
-			static HMODULE glMod = GetModuleHandleA("opengl32.dll");
+			static HMODULE image = GetModuleHandleA("opengl32.dll");
 		
-			PROC pFunc = wglGetProcAddress(reinterpret_cast<LPCSTR>(name));
-			if(TestPointer(pFunc))
+			PROC func = wglGetProcAddress(reinterpret_cast<LPCSTR>(name));
+			if (test_pointer(func))
 			{
-				return reinterpret_cast<void*>(pFunc);
+				return reinterpret_cast<void*>(func);
 			}
 		
-			return reinterpret_cast<void*>GetProcAddress(glMod, reinterpret_cast<LPCSTR>(name));
+			return reinterpret_cast<void*>(GetProcAddress(image, reinterpret_cast<LPCSTR>(name)));
 		}
 			
 		#else // GLX