diff --git a/core/src/main/java/com/google/bitcoin/core/MemoryPool.java b/core/src/main/java/com/google/bitcoin/core/MemoryPool.java
index bb22917ea..533a10694 100644
--- a/core/src/main/java/com/google/bitcoin/core/MemoryPool.java
+++ b/core/src/main/java/com/google/bitcoin/core/MemoryPool.java
@@ -268,8 +268,8 @@ public class MemoryPool {
     private void markBroadcast(PeerAddress byPeer, Transaction tx) {
         checkState(lock.isHeldByCurrentThread());
         final TransactionConfidence confidence = tx.getConfidence();
-        confidence.markBroadcastBy(byPeer);
-        confidence.queueListeners(TransactionConfidence.Listener.ChangeReason.SEEN_PEERS);
+        if (confidence.markBroadcastBy(byPeer))
+            confidence.queueListeners(TransactionConfidence.Listener.ChangeReason.SEEN_PEERS);
     }
 
     /**
diff --git a/core/src/main/java/com/google/bitcoin/core/TransactionConfidence.java b/core/src/main/java/com/google/bitcoin/core/TransactionConfidence.java
index f1df3a264..4d56d62ff 100644
--- a/core/src/main/java/com/google/bitcoin/core/TransactionConfidence.java
+++ b/core/src/main/java/com/google/bitcoin/core/TransactionConfidence.java
@@ -274,12 +274,13 @@ public class TransactionConfidence implements Serializable {
      *
      * @param address IP address of the peer, used as a proxy for identity.
      */
-    public synchronized void markBroadcastBy(PeerAddress address) {
+    public synchronized boolean markBroadcastBy(PeerAddress address) {
         if (!broadcastBy.addIfAbsent(address))
-            return;  // Duplicate.
+            return false;  // Duplicate.
         if (getConfidenceType() == ConfidenceType.UNKNOWN) {
             this.confidenceType = ConfidenceType.PENDING;
         }
+        return true;
     }
 
     /**