diff --git a/lib/galaxy/tool_util_models/tool_source.py b/lib/galaxy/tool_util_models/tool_source.py
index 88f0452a062..b4c2fbeea61 100644
--- a/lib/galaxy/tool_util_models/tool_source.py
+++ b/lib/galaxy/tool_util_models/tool_source.py
@@ -216,7 +216,6 @@ BaseJsonTestCollectionDefCollectionElementDict = TypedDict(
         "class": Literal["Collection"],
         "collection_type": Optional[str],
         "elements": NotRequired[Optional[List[JsonTestCollectionDefElementDict]]],
-        "fields": NotRequired[Optional[List[FieldDict]]],
     },
 )