diff --git a/scripts/startup/bl_ui/properties_grease_pencil_common.py b/scripts/startup/bl_ui/properties_grease_pencil_common.py
index 1403bb0d07e..c4bf9adac35 100644
--- a/scripts/startup/bl_ui/properties_grease_pencil_common.py
+++ b/scripts/startup/bl_ui/properties_grease_pencil_common.py
@@ -287,6 +287,8 @@ class GPENCIL_MT_material_active(Menu):
 
         for slot in ob.material_slots:
             mat = slot.material
+            if not mat:
+                continue
             mat.id_data.preview_ensure()
             if mat and mat.id_data and mat.id_data.preview:
                 icon = mat.id_data.preview.icon_id