diff --git a/loopy/kernel/array.py b/loopy/kernel/array.py
index 97bc02dfd..b6ed5518d 100644
--- a/loopy/kernel/array.py
+++ b/loopy/kernel/array.py
@@ -892,6 +892,11 @@ def __init__(self, name, dtype=None, shape=None, dim_tags=None, offset=0,
                 tags=tags,
                 **kwargs)
 
+    # Without this __hash__ is set to None because this class overrides __eq__.
+    # Source: https://docs.python.org/3/reference/datamodel.html#object.__hash__
+    def __hash__(self):
+        return super().__hash__()
+
     def __eq__(self, other):
         from loopy.symbolic import (
                 is_tuple_of_expressions_equal as istoee,
diff --git a/loopy/transform/iname.py b/loopy/transform/iname.py
index e61b85be3..e55bad50c 100644
--- a/loopy/transform/iname.py
+++ b/loopy/transform/iname.py
@@ -935,7 +935,8 @@ def duplicate_inames(kernel, inames, within, new_inames=None, suffix=None,
             within=within)
 
     def _does_access_old_inames(kernel, insn, *args):
-        return bool(frozenset(inames) & insn.dependency_names())
+        return bool(frozenset(inames) & (insn.dependency_names()
+                                         | insn.reduction_inames()))
 
     kernel = rule_mapping_context.finish_kernel(
             indup.map_kernel(kernel, within=_does_access_old_inames,
diff --git a/test/test_transform.py b/test/test_transform.py
index 27f55c760..3915ce161 100644
--- a/test/test_transform.py
+++ b/test/test_transform.py
@@ -1324,6 +1324,19 @@ def test_precompute_does_not_lead_to_dep_cycle(ctx_factory):
     lp.auto_test_vs_ref(knl, ctx, ref_knl)
 
 
+def test_rename_inames_redn():
+    t_unit = lp.make_kernel(
+        "{[i, j0, j1]: 0<=i, j0, j1<10}",
+        """
+        y0[i] = sum(j0, sum([j1], 2*A[i, j0, j1]))
+        """)
+
+    t_unit = lp.rename_iname(t_unit, "j1", "ifused")
+
+    assert "j1" not in t_unit.default_entrypoint.all_inames()
+    assert "ifused" in t_unit.default_entrypoint.all_inames()
+
+
 if __name__ == "__main__":
     if len(sys.argv) > 1:
         exec(sys.argv[1])