diff --git a/src/cluster.c b/src/cluster.c
index 88c927d5..f9899fae 100644
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -1363,7 +1363,7 @@ int clusterProcessPacket(clusterLink *link) {
                 }
 
                 /* Master node changed for this slave? */
-                if (sender->slaveof != master) {
+                if (master && sender->slaveof != master) {
                     if (sender->slaveof)
                         clusterNodeRemoveSlave(sender->slaveof,sender);
                     clusterNodeAddSlave(master,sender);