--- a/src/zookeeper.c
+++ b/src/zookeeper.c
@@ -3477,7 +3477,7 @@
 
 static const char* format_endpoint_info(const struct sockaddr_storage* ep)
 {
-    static char buf[128];
+    static char buf[128 + 6];	// include space for the port :xxxxx
     char addrstr[128];
     void *inaddr;
 #ifdef WIN32