--- bin/kafka-server-start.sh.orig	2011-10-03 12:06:55.000000000 +0200
+++ bin/kafka-server-start.sh	2011-10-03 11:54:20.000000000 +0200
@@ -6,6 +6,6 @@
 	exit 1
 fi
 
-export JMX_PORT="9999"
+export JMX_PORT=${JMX_PORT:-9999}
 
 $(dirname $0)/kafka-run-class.sh kafka.Kafka $@