diff --git a/src/blenderbim/blenderbim/bim/module/material/ui.py b/src/blenderbim/blenderbim/bim/module/material/ui.py
index e823f32938..ad2f2e4155 100644
--- a/src/blenderbim/blenderbim/bim/module/material/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/material/ui.py
@@ -150,7 +150,7 @@ class BIM_PT_object_material(Panel):
         if not ObjectMaterialData.data["materials"]:
             row = self.layout.row(align=True)
             row.label(text="No Materials Available")
-            row.operator("bim.add_material", icon="ADD", text="").obj = ""
+            row.operator("bim.add_material", icon="ADD", text="")
             return
 
         if ObjectMaterialData.data["type_material"]: