diff --git a/python/cudf/cudf/core/frame.py b/python/cudf/cudf/core/frame.py
index ae4f6180eec..5d33fbf70c3 100644
--- a/python/cudf/cudf/core/frame.py
+++ b/python/cudf/cudf/core/frame.py
@@ -1234,9 +1234,6 @@ def isna(self):
         data_columns = (col.isnull() for col in self._columns)
         return self._from_data_like_self(zip(self._column_names, data_columns))
 
-    # Alias for isna
-    isnull = isna
-
     @_cudf_nvtx_annotate
     def notna(self):
         """
diff --git a/python/cudf/cudf/core/indexed_frame.py b/python/cudf/cudf/core/indexed_frame.py
index efa75772053..6443391bfe1 100644
--- a/python/cudf/cudf/core/indexed_frame.py
+++ b/python/cudf/cudf/core/indexed_frame.py
@@ -1238,6 +1238,9 @@ def tail(self, n=5):
 
         return self.iloc[-n:]
 
+    # Alias for isna
+    isnull = Frame.isna
+
     def _copy_type_metadata(
         self,
         other: Self,