diff --git a/server/statistics/region_collection.go b/server/statistics/region_collection.go
index 7b354ce9f54..8d4d6d1849c 100644
--- a/server/statistics/region_collection.go
+++ b/server/statistics/region_collection.go
@@ -283,6 +283,7 @@ func (r *RegionStatistics) ClearDefunctRegion(regionID uint64) {
 		}
 	}
 	if oldIndex, ok := r.offlineIndex[regionID]; ok {
+		delete(r.offlineIndex, regionID)
 		r.deleteOfflineEntry(oldIndex, regionID)
 	}
 }
diff --git a/server/statistics/region_collection_test.go b/server/statistics/region_collection_test.go
index 6f27443b24f..aa5a8399ab6 100644
--- a/server/statistics/region_collection_test.go
+++ b/server/statistics/region_collection_test.go
@@ -129,6 +129,10 @@ func TestRegionStatistics(t *testing.T) {
 	stores[3] = store3
 	regionStats.Observe(region1, stores)
 	re.Empty(regionStats.stats[OfflinePeer])
+
+	regionStats.ClearDefunctRegion(1)
+	re.Equal(1, len(regionStats.index))
+	re.Equal(1, len(regionStats.offlineIndex))
 }
 
 func TestRegionStatisticsWithPlacementRule(t *testing.T) {