diff --git a/Source/OpenTK/Graphics/GL/GLHelper.cs b/Source/OpenTK/Graphics/GL/GLHelper.cs
index 204e9eea..3e95f98e 100644
--- a/Source/OpenTK/Graphics/GL/GLHelper.cs
+++ b/Source/OpenTK/Graphics/GL/GLHelper.cs
@@ -335,39 +335,24 @@ namespace OpenTK.Graphics
 
         #endregion
 
-        #region static bool SupportsFunction(Type function)
+        #region static bool SupportsFunction(MethodInfo function)
 
         /// <summary>
-        /// Checks if a given OpenGL function is supported by the current context
+        /// Checks if a given OpenGL function is supported by the current context.
         /// </summary>
-        /// <param name="method">The System.Reflection.MethodInfo of the OpenGL function.</param>
-        /// <returns>True if the function is supported, false otherwise</returns>
-        static bool SupportsFunction(MethodInfo method)
+        /// <param name="method">The System.Reflection.MethodInfo for the OpenGL function.</param>
+        /// <returns>True if the function is supported, false otherwise.</returns>
+        static bool SupportsFunction(MethodInfo function)
         {
-            throw new NotImplementedException();
-#if false
-            lock (gl_lock)
-            {
-                
-                if (function == null)
-                    throw new ArgumentNullException("function");
+            if (function == null)
+                throw new ArgumentNullException("function");
 
-                sb.Remove(0, sb.Length);
-                if (!function.Name.StartsWith("gl"))
-                    sb.Append("gl");
-                sb.Append(function);
-                //if (!function.EndsWith(extension))
-                //    sb.Append(extension);
-
-                FieldInfo f = delegatesClass.GetField(sb.ToString(), BindingFlags.Static | BindingFlags.NonPublic);
-                if (f == null)
-                    return false;
-
-                return f.GetValue(null) != null;
-                
+            AutoGeneratedAttribute[] attr = (AutoGeneratedAttribute[])
+                function.GetCustomAttributes(typeof(AutoGeneratedAttribute), false);
+            if (attr.Length == 0)
                 return false;
-            }
-#endif
+
+            return SupportsFunction(attr[0].EntryPoint);
         }
 
         #endregion