diff --git a/render_povray/ui.py b/render_povray/ui.py
index e156c5e72b81b9f9eaaada3b010d4a963f4718d7..d1c0b76975caf0f749b00478d2bff589a1692090 100644
--- a/render_povray/ui.py
+++ b/render_povray/ui.py
@@ -104,7 +104,7 @@ class MaterialButtonsPanel():
     def poll(cls, context):
         mat = context.material
         rd = context.scene.render
-        return (rd.use_game_engine == False) and (rd.engine in cls.COMPAT_ENGINES)
+        return mat and (rd.use_game_engine == False) and (rd.engine in cls.COMPAT_ENGINES)
 
 ########################################MR######################################
 class MATERIAL_PT_povray_mirrorIOR(MaterialButtonsPanel, bpy.types.Panel):