diff --git a/test/src/main/java/org/jvnet/hudson/test/HudsonTestCase.java b/test/src/main/java/org/jvnet/hudson/test/HudsonTestCase.java
index a70fc769a857b9c9e334e8f92d8553e352ea7019..1b92d0a0ee59373eb06c5b2b608934e5648bbc74 100644
--- a/test/src/main/java/org/jvnet/hudson/test/HudsonTestCase.java
+++ b/test/src/main/java/org/jvnet/hudson/test/HudsonTestCase.java
@@ -18,6 +18,7 @@ import hudson.model.UpdateCenter;
 import hudson.model.Saveable;
 import hudson.model.Run;
 import hudson.model.Result;
+import hudson.model.JDK;
 import hudson.tasks.Mailer;
 import hudson.Launcher.LocalLauncher;
 import hudson.util.StreamTaskListener;
@@ -113,6 +114,9 @@ public abstract class HudsonTestCase extends TestCase {
         hudson.servletContext.setAttribute("app",hudson);
         hudson.servletContext.setAttribute("version","?");
 
+        // set a default JDK to be the one that the harness is using.
+        hudson.getJDKs().add(new JDK("default",System.getProperty("java.home")));
+
         // cause all the descriptors to reload.
         // ideally we'd like to reset them to properly emulate the behavior, but that's not possible.
         Mailer.DESCRIPTOR.setHudsonUrl(null);