diff --git a/core/src/main/java/jenkins/model/Jenkins.java b/core/src/main/java/jenkins/model/Jenkins.java
index 942088b1c23621e3f30a3d81c82fa1f356c64810..d584cd0f768f02a66ac278a6c0dc27e33a1a3bdc 100644
--- a/core/src/main/java/jenkins/model/Jenkins.java
+++ b/core/src/main/java/jenkins/model/Jenkins.java
@@ -566,7 +566,7 @@ public class Jenkins extends AbstractCIBase implements DirectlyModifiableTopLeve
      * TCP slave agent port.
      * 0 for random, -1 to disable.
      */
-    private int slaveAgentPort =0;
+    private int slaveAgentPort = Integer.getInteger(Jenkins.class.getName()+".slaveAgentPort",0);
 
     /**
      * Whitespace-separated labels assigned to the master as a {@link Node}.