diff --git a/discord/enums.py b/discord/enums.py
index 7aa211768..43ae5b4f7 100644
--- a/discord/enums.py
+++ b/discord/enums.py
@@ -547,7 +547,7 @@ class StickerFormatType(Enum):
             StickerFormatType.gif: 'gif',
         }
         # fmt: on
-        return lookup[self]
+        return lookup.get(self, 'png')
 
 
 class InviteTarget(Enum):