diff --git a/loopy/schedule/__init__.py b/loopy/schedule/__init__.py
index 652f8b8933ee79935f8bf08e7de2356972922ccc..58b68486be3e08a818cc87388eea31f0788bb959 100644
--- a/loopy/schedule/__init__.py
+++ b/loopy/schedule/__init__.py
@@ -794,9 +794,13 @@ def generate_loop_schedules_internal(
 
         if not is_ready:
             if debug_mode:
-                print("instruction '%s' is missing insn depedencies '%s'" % (
-                        format_insn(kernel, insn.id), ",".join(
-                            insn.depends_on - sched_state.scheduled_insn_ids)))
+                # These are not that interesting when understanding scheduler
+                # failures.
+
+                # print("instruction '%s' is missing insn depedencies '%s'" % (
+                #         format_insn(kernel, insn.id), ",".join(
+                #             insn.depends_on - sched_state.scheduled_insn_ids)))
+                pass
             continue
 
         want = kernel.insn_inames(insn) - sched_state.parallel_inames
diff --git a/test/test_reduction.py b/test/test_reduction.py
index 78eca4d0c141526d9bac652d5baa3890933ac0c1..ef229d5cd08554d6656d23d83bc0c6b66ee77b9f 100644
--- a/test/test_reduction.py
+++ b/test/test_reduction.py
@@ -225,22 +225,28 @@ def test_global_parallel_reduction(ctx_factory, size):
             "{[i]: 0 <= i < n }",
             """
             # Using z[0] instead of z works around a bug in ancient PyOpenCL.
-            z[0] = sum(i, i/13)
+            z[0] = sum(i, a[i])
             """)
 
+    knl = lp.add_and_infer_dtypes(knl, {"a": np.float32})
     ref_knl = knl
 
     gsize = 128
     knl = lp.split_iname(knl, "i", gsize * 20)
-    knl = lp.split_iname(knl, "i_inner", gsize, outer_tag="l.0")
-    knl = lp.split_reduction_inward(knl, "i_inner_inner")
+    knl = lp.split_iname(knl, "i_inner", gsize, inner_tag="l.0")
+    knl = lp.split_reduction_outward(knl, "i_outer")
     knl = lp.split_reduction_inward(knl, "i_inner_outer")
     from loopy.transform.data import reduction_arg_to_subst_rule
     knl = reduction_arg_to_subst_rule(knl, "i_outer")
+
     knl = lp.precompute(knl, "red_i_outer_arg", "i_outer",
             temporary_scope=lp.temp_var_scope.GLOBAL,
             default_tag="l.auto")
     knl = lp.realize_reduction(knl)
+    knl = lp.tag_inames(knl, "i_outer_0:g.0")
+
+    # Keep the i_outer accumulator on the  correct (lower) side of the barrier,
+    # otherwise there will be useless save/reload code generated.
     knl = lp.add_dependency(
             knl, "writes:acc_i_outer",
             "id:red_i_outer_arg_barrier")