diff --git a/src/main/java/org/commoncrawl/webgraph/explore/Graph.java b/src/main/java/org/commoncrawl/webgraph/explore/Graph.java
index 1b944e4..6fec31a 100644
--- a/src/main/java/org/commoncrawl/webgraph/explore/Graph.java
+++ b/src/main/java/org/commoncrawl/webgraph/explore/Graph.java
@@ -255,8 +255,11 @@ public Stream<Entry<String, Long>> topLevelDomainCounts(IntStream vertexIds) {
 						}
 						count++;
 					}
-					curr = next;
 					res.add(new SimpleEntry<>(tld, count));
+					curr = next;
+					if (!iter.hasNext()) {
+						break;
+					}
 				} while (curr > -1);
 			}
 			return res.stream().sorted(Collections.reverseOrder(Map.Entry.comparingByValue()));