diff --git a/server/schedulers/balance_test.go b/server/schedulers/balance_test.go
index 893a75734a5..6447643d28c 100644
--- a/server/schedulers/balance_test.go
+++ b/server/schedulers/balance_test.go
@@ -909,6 +909,9 @@ func (s *testBalanceHotWriteRegionSchedulerSuite) TestBalance(c *C) {
 	opt.HotRegionScheduleLimit = mockoption.NewScheduleOptions().HotRegionScheduleLimit
 	opt.RegionScheduleLimit = 0
 	c.Assert(hb.Schedule(tc), HasLen, 1)
+	// Always produce operator
+	c.Assert(hb.Schedule(tc), HasLen, 1)
+	c.Assert(hb.Schedule(tc), HasLen, 1)
 
 	//| region_id | leader_store | follower_store | follower_store | written_bytes |
 	//|-----------|--------------|----------------|----------------|---------------|
diff --git a/server/schedulers/hot_region.go b/server/schedulers/hot_region.go
index 44b57c4eb0b..2ad7002f8ff 100644
--- a/server/schedulers/hot_region.go
+++ b/server/schedulers/hot_region.go
@@ -128,20 +128,13 @@ func (h *balanceHotRegionsScheduler) IsScheduleAllowed(cluster schedule.Cluster)
 	return h.allowBalanceLeader(cluster) || h.allowBalanceRegion(cluster)
 }
 
-func min(a, b uint64) uint64 {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 func (h *balanceHotRegionsScheduler) allowBalanceLeader(cluster schedule.Cluster) bool {
-	return h.opController.OperatorCount(schedule.OpHotRegion) < min(h.leaderLimit, cluster.GetHotRegionScheduleLimit()) &&
+	return h.opController.OperatorCount(schedule.OpHotRegion) < minUint64(h.leaderLimit, cluster.GetHotRegionScheduleLimit()) &&
 		h.opController.OperatorCount(schedule.OpLeader) < cluster.GetLeaderScheduleLimit()
 }
 
 func (h *balanceHotRegionsScheduler) allowBalanceRegion(cluster schedule.Cluster) bool {
-	return h.opController.OperatorCount(schedule.OpHotRegion) < min(h.peerLimit, cluster.GetHotRegionScheduleLimit())
+	return h.opController.OperatorCount(schedule.OpHotRegion) < minUint64(h.peerLimit, cluster.GetHotRegionScheduleLimit())
 }
 
 func (h *balanceHotRegionsScheduler) Schedule(cluster schedule.Cluster) []*schedule.Operator {
@@ -443,7 +436,8 @@ func (h *balanceHotRegionsScheduler) adjustBalanceLimit(storeID uint64, storesSt
 
 	avgRegionCount := hotRegionTotalCount / float64(len(storesStat))
 	// Multiplied by hotRegionLimitFactor to avoid transfer back and forth
-	return uint64((float64(srcStoreStatistics.RegionsStat.Len()) - avgRegionCount) * hotRegionLimitFactor)
+	limit := uint64((float64(srcStoreStatistics.RegionsStat.Len()) - avgRegionCount) * hotRegionLimitFactor)
+	return maxUint64(limit, 1)
 }
 
 func (h *balanceHotRegionsScheduler) GetHotReadStatus() *statistics.StoreHotRegionInfos {