diff --git a/weed/topology/topology.go b/weed/topology/topology.go
index 0d393bdfd9..81db2ff59a 100644
--- a/weed/topology/topology.go
+++ b/weed/topology/topology.go
@@ -813,11 +813,9 @@ func (t *Topology) ListCollections(includeNormalVolumes, includeEcVolumes bool)
 	found := make(map[string]bool)
 
 	if includeNormalVolumes {
-		t.collectionMap.RLock()
 		for _, c := range t.collectionMap.Items() {
 			found[c.(*Collection).Name] = true
 		}
-		t.collectionMap.RUnlock()
 	}
 
 	if includeEcVolumes {
diff --git a/weed/topology/topology_test.go b/weed/topology/topology_test.go
index 681d9f282d..4c3e34b62e 100644
--- a/weed/topology/topology_test.go
+++ b/weed/topology/topology_test.go
@@ -641,6 +641,40 @@ func TestListCollections(t *testing.T) {
 	}
 }
 
+// A collection delete that queues for the write lock while ListCollections
+// reads the collections must not wedge both.
+func TestListCollectionsWithConcurrentCollectionDelete(t *testing.T) {
+	rp, _ := super_block.NewReplicaPlacementFromString("000")
+	topo := NewTopology("weedfs", sequence.NewMemorySequencer(), 32*1024, 5, false)
+
+	stop := make(chan struct{})
+	defer close(stop)
+	go func() {
+		for {
+			select {
+			case <-stop:
+				return
+			default:
+			}
+			topo.GetVolumeLayout("churn", rp, needle.EMPTY_TTL, types.HardDriveType)
+			topo.DeleteCollection("churn")
+		}
+	}()
+
+	listed := make(chan struct{})
+	go func() {
+		defer close(listed)
+		for i := 0; i < 100000; i++ {
+			topo.ListCollections(true, false)
+		}
+	}()
+	select {
+	case <-listed:
+	case <-time.After(10 * time.Second):
+		t.Fatal("ListCollections deadlocked with a concurrent DeleteCollection")
+	}
+}
+
 func TestDataNodeIdBasedIdentification(t *testing.T) {
 	topo := NewTopology("weedfs", sequence.NewMemorySequencer(), 32*1024, 5, false)
 	dc := topo.GetOrCreateDataCenter("dc1")