diff --git a/include/tvm/topi/cuda/reduction.h b/include/tvm/topi/cuda/reduction.h
index 7160419422a6..51f35ed8dc25 100644
--- a/include/tvm/topi/cuda/reduction.h
+++ b/include/tvm/topi/cuda/reduction.h
@@ -70,7 +70,7 @@ Schedule ScheduleReduce(const Target& target, Operation op, Schedule sch,
   if (out_stage->op.as<ComputeOpNode>()->axis.size() > 0) {
     all_reduce = false;
     num_thread = 32;
-    if (target->kind->name == "opencl") {
+    if (target->kind->name == "opencl" || target->kind->name == "metal") {
       // Without this, CL_INVALID_WORK_GROUP_SIZE occurs with python tests.
       // Don't know why.
       num_thread = 16;
diff --git a/python/tvm/topi/cuda/reduction.py b/python/tvm/topi/cuda/reduction.py
index ceab71640533..b9d02d9c81d8 100644
--- a/python/tvm/topi/cuda/reduction.py
+++ b/python/tvm/topi/cuda/reduction.py
@@ -37,7 +37,7 @@ def _schedule_reduce(op, sch, is_idx_reduce=False):
         all_reduce = False
         num_thread = 32
         target = tvm.target.Target.current()
-        if target and target.kind.name == "opencl":
+        if target and (target.kind.name == "opencl" or target.kind.name == "metal"):
             # without it, CL_INVALID_WORK_GROUP_SIZE occurred when running test_topi_reduce.py
             # don't know why
             num_thread = 16