--- a/gfx/layers/composite/TextureHost.h
+++ b/gfx/layers/composite/TextureHost.h
@@ -106,17 +106,20 @@ public:
   /**
    * Return the pixel format of this texture
    */
   virtual gfx::SurfaceFormat GetFormat() const { return gfx::SurfaceFormat::UNKNOWN; }
 
   /**
    * Cast to a TextureSource for for each backend..
    */
-  virtual TextureSourceOGL* AsSourceOGL() { return nullptr; }
+  virtual TextureSourceOGL* AsSourceOGL() {
+    gfxCriticalNote << "Failed to cast " << Name() << " into a TextureSourceOGL";
+    return nullptr;
+  }
   virtual TextureSourceD3D9* AsSourceD3D9() { return nullptr; }
   virtual TextureSourceD3D11* AsSourceD3D11() { return nullptr; }
   virtual TextureSourceBasic* AsSourceBasic() { return nullptr; }
   /**
    * Cast to a DataTextureSurce.
    */
   virtual DataTextureSource* AsDataTextureSource() { return nullptr; }