diff --git a/stac_model/schema.py b/stac_model/schema.py
index 63310ba..008d7ec 100644
--- a/stac_model/schema.py
+++ b/stac_model/schema.py
@@ -173,7 +173,7 @@ class SummariesMLModelExtension(SummariesExtension):
 
     def _check_mlm_property(self, prop: str) -> FieldInfo:
         try:
-            return MLModelProperties.model_fields[prop]
+            return MLModelProperties.model_fields[prop]  # type: ignore
         except KeyError as err:
             raise AttributeError(f"Name '{prop}' is not a valid MLM property.") from err