diff --git a/altair/vegalite/v5/api.py b/altair/vegalite/v5/api.py
index 56b15db79..05e088b6d 100644
--- a/altair/vegalite/v5/api.py
+++ b/altair/vegalite/v5/api.py
@@ -431,7 +431,7 @@ def param(
             name=parameter.name,
             bind=bind,
             value=value,
-            expr=expr,  # type: ignore[arg-type]
+            expr=expr,
             **kwds,
         )
         parameter.param_type = "variable"