diff --git a/mlir/python/mlir/dialects/pdl.py b/mlir/python/mlir/dialects/pdl.py
index 90d7d706238e6..800be6d91b753 100644
--- a/mlir/python/mlir/dialects/pdl.py
+++ b/mlir/python/mlir/dialects/pdl.py
@@ -216,7 +216,5 @@ def __init__(
         loc=None,
         ip=None,
     ):
-        if constantTypes is None:
-            constantTypes = []
         result = pdl.RangeType.get(pdl.TypeType.get())
         super().__init__(result, constantTypes=constantTypes, loc=loc, ip=ip)