diff --git a/starboard/events.py b/starboard/events.py
index 605cfc3dd1..b1c3afc77a 100644
--- a/starboard/events.py
+++ b/starboard/events.py
@@ -135,7 +135,7 @@ async def _build_embed(
                             name="Attachment",
                             value=f"||[{attachment.filename}]({attachment.url})||",
                         )
-                    elif not attachment.url.lower().endswith(
+                    elif not attachment.filename.lower().endswith(
                         ("png", "jpeg", "jpg", "gif", "webp")
                     ):
                         new_em.add_field(