diff --git a/init.groovy b/init.groovy
index a42a733..2f9f129 100644
--- a/init.groovy
+++ b/init.groovy
@@ -5,6 +5,6 @@
 Thread.start {
       sleep 10000
       println "--> setting agent port for jnlp"
-      Jenkins.instance.setSlaveAgentPort(50000)
+      Jenkins.instance.setSlaveAgentPort(env['JENKINS_SLAVE_AGENT_PORT'])
       println "--> setting agent port for jnlp... done"
 }