diff --git a/router/java/src/net/i2p/router/JobQueue.java b/router/java/src/net/i2p/router/JobQueue.java
index 1a65ac8953..a29ace0368 100644
--- a/router/java/src/net/i2p/router/JobQueue.java
+++ b/router/java/src/net/i2p/router/JobQueue.java
@@ -211,10 +211,14 @@ public class JobQueue {
     /**
      * Returns <code>true</code> if a given job is waiting or running;
      * <code>false</code> if the job is finished or doesn't exist in the queue.
+     *
+     * Only used by PluginStarter, candidate for deprecation
      */
     public boolean isJobActive(Job job) {
-        if (_readyJobs.contains(job) || _timedJobs.contains(job))
-            return true;
+        synchronized (_jobLock) {
+            if (_readyJobs.contains(job) || _timedJobs.contains(job))
+                return true;
+        }
         for (JobQueueRunner runner: _queueRunners.values())
             if (runner.getCurrentJob() == job)
                 return true;