diff --git a/src/java/org/apache/cassandra/service/ConsistencyManager.java b/src/java/org/apache/cassandra/service/ConsistencyManager.java
index 226144952a..c55b6c7b83 100644
--- a/src/java/org/apache/cassandra/service/ConsistencyManager.java
+++ b/src/java/org/apache/cassandra/service/ConsistencyManager.java
@@ -110,7 +110,7 @@ class ConsistencyManager implements Runnable
 			majority_ = (responseCount >> 1) + 1;  
 		}
 		
-		public void response(Message message)
+		public synchronized void response(Message message)
 		{
 			if (logger_.isDebugEnabled())
 			  logger_.debug("Received responses in DataRepairHandler : " + message.toString());