diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index 61fa5c49a8c5b..351227c216118 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -7047,7 +7047,7 @@ def fillna(
                         # see test_fillna_dict_inplace_nonunique_columns
                         locs = result.columns.get_loc(k)
                         if isinstance(locs, slice):
-                            locs = np.arange(self.shape[1])[locs]
+                            locs = range(self.shape[1])[locs]
                         elif isinstance(locs, np.ndarray) and locs.dtype.kind == "b":
                             locs = locs.nonzero()[0]
                         elif not (
diff --git a/pandas/core/indexing.py b/pandas/core/indexing.py
index debb5bdd4fc4b..08bd3cde60806 100644
--- a/pandas/core/indexing.py
+++ b/pandas/core/indexing.py
@@ -2308,11 +2308,11 @@ def _ensure_iterable_column_indexer(self, column_indexer):
         """
         Ensure that our column indexer is something that can be iterated over.
         """
-        ilocs: Sequence[int | np.integer] | np.ndarray
+        ilocs: Sequence[int | np.integer] | np.ndarray | range
         if is_integer(column_indexer):
             ilocs = [column_indexer]
         elif isinstance(column_indexer, slice):
-            ilocs = np.arange(len(self.obj.columns))[column_indexer]
+            ilocs = range(len(self.obj.columns))[column_indexer]
         elif (
             isinstance(column_indexer, np.ndarray) and column_indexer.dtype.kind == "b"
         ):