diff --git a/src/de/uni_leipzig/informatik/asv/gephi/chinesewhispers/ChineseWhispersClusterer.java b/src/de/uni_leipzig/informatik/asv/gephi/chinesewhispers/ChineseWhispersClusterer.java
index 3ba6a37..57e0fec 100644
--- a/src/de/uni_leipzig/informatik/asv/gephi/chinesewhispers/ChineseWhispersClusterer.java
+++ b/src/de/uni_leipzig/informatik/asv/gephi/chinesewhispers/ChineseWhispersClusterer.java
@@ -91,6 +91,7 @@ public void execute(GraphModel gm) {
         for (Node node : graph.getNodes()) {
           if (unconnected == Unconnected.INDIVIDUAL) classes.put(node, counter++);
           if (graph.getNeighbors(node).iterator().hasNext()) {
+              graph.readUnlock();
               connectedNodes.add(node);
               if (unconnected != Unconnected.INDIVIDUAL) classes.put(node, counter++);
           }