diff --git a/panda/src/display/graphicsStateGuardian.cxx b/panda/src/display/graphicsStateGuardian.cxx
index aab3814dd3..31677062c7 100644
--- a/panda/src/display/graphicsStateGuardian.cxx
+++ b/panda/src/display/graphicsStateGuardian.cxx
@@ -2972,6 +2972,18 @@ make_shadow_buffer(const NodePath &light_np, GraphicsOutputBase *host) {
   return tex;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: GraphicsStateGuardian::has_extension
+//       Access: Public, Virtual
+//  Description: Returns true if the GSG implements the extension
+//               identified by the given string.  This currently
+//               is only implemented by the OpenGL back-end.
+////////////////////////////////////////////////////////////////////
+bool GraphicsStateGuardian::
+has_extension(const string &extension) const {
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: GraphicsStateGuardian::get_driver_vendor
 //       Access: Public, Virtual
diff --git a/panda/src/display/graphicsStateGuardian.h b/panda/src/display/graphicsStateGuardian.h
index deec626996..31282aa820 100644
--- a/panda/src/display/graphicsStateGuardian.h
+++ b/panda/src/display/graphicsStateGuardian.h
@@ -201,6 +201,7 @@ PUBLISHED:
 #endif
 
 PUBLISHED:
+  virtual bool has_extension(const string &extension) const;
 
   virtual string get_driver_vendor();
   virtual string get_driver_renderer();
diff --git a/panda/src/glstuff/glGraphicsStateGuardian_src.I b/panda/src/glstuff/glGraphicsStateGuardian_src.I
index f776d69c2e..2831d5a3d3 100644
--- a/panda/src/glstuff/glGraphicsStateGuardian_src.I
+++ b/panda/src/glstuff/glGraphicsStateGuardian_src.I
@@ -171,6 +171,25 @@ maybe_gl_finish() const {
 #endif
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: GLGraphicsStateGuardian::has_extension
+//       Access: Published, Final
+//  Description: Returns true if the indicated extension is reported
+//               by the GL system, false otherwise.  The extension
+//               name is case-sensitive.
+////////////////////////////////////////////////////////////////////
+INLINE bool CLP(GraphicsStateGuardian)::
+has_extension(const string &extension) const {
+  bool has_ext = (_extensions.find(extension) != _extensions.end());
+#ifndef NDEBUG
+  if (GLCAT.is_debug()) {
+    GLCAT.debug()
+      << "HAS EXT " << extension << " " << has_ext << "\n";
+  }
+#endif
+  return has_ext;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: GLGraphicsStateGuardian::is_at_least_gl_version
 //       Access: Public
diff --git a/panda/src/glstuff/glGraphicsStateGuardian_src.cxx b/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
index c297540492..877440e148 100644
--- a/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
+++ b/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
@@ -6781,27 +6781,6 @@ report_extensions() const {
   }
 }
 
-////////////////////////////////////////////////////////////////////
-//     Function: GLGraphicsStateGuardian::has_extension
-//       Access: Protected
-//  Description: Returns true if the indicated extension is reported
-//               by the GL system, false otherwise.  The extension
-//               name is case-sensitive.
-////////////////////////////////////////////////////////////////////
-bool CLP(GraphicsStateGuardian)::
-has_extension(const string &extension) const {
-
-  bool state;
-
-  state = _extensions.find(extension) != _extensions.end();
-  if (GLCAT.is_debug()) {
-    GLCAT.debug()
-      << "HAS EXT " << extension << " " << state << "\n";
-  }
-
-  return state;
-}
-
 ////////////////////////////////////////////////////////////////////
 //     Function: GLGraphicsStateGuardian::get_extension_func
 //       Access: Public
diff --git a/panda/src/glstuff/glGraphicsStateGuardian_src.h b/panda/src/glstuff/glGraphicsStateGuardian_src.h
index 5b331abbc1..4895feced0 100644
--- a/panda/src/glstuff/glGraphicsStateGuardian_src.h
+++ b/panda/src/glstuff/glGraphicsStateGuardian_src.h
@@ -406,7 +406,7 @@ protected:
   void save_extensions(const char *extensions);
   virtual void get_extra_extensions();
   void report_extensions() const;
-  bool has_extension(const string &extension) const;
+  INLINE virtual bool has_extension(const string &extension) const FINAL;
   INLINE bool is_at_least_gl_version(int major_version, int minor_version) const;
   INLINE bool is_at_least_gles_version(int major_version, int minor_version) const;
   void *get_extension_func(const char *name);