diff --git a/core/src/main/java/hudson/util/DoubleLaunchChecker.java b/core/src/main/java/hudson/util/DoubleLaunchChecker.java
index e6d6155f4e63438ac0b86f3f4bf302ddddd50e9d..d65068ac7ff35a1f465f561c8e4f3accad596ea1 100644
--- a/core/src/main/java/hudson/util/DoubleLaunchChecker.java
+++ b/core/src/main/java/hudson/util/DoubleLaunchChecker.java
@@ -127,7 +127,7 @@ public class DoubleLaunchChecker {
         String contextPath="";
         try {
             Method m = ServletContext.class.getMethod("getContextPath");
-            contextPath=(String)m.invoke(h.servletContext);
+            contextPath=" contextPath=\""+m.invoke(h.servletContext)+"\"";
         } catch (Exception e) {
             // maybe running with Servlet 2.4
         }