diff --git a/lib/cluster/services/jobs.js b/lib/cluster/services/jobs.js
index 111c0ec94ef..e3242aef3cc 100644
--- a/lib/cluster/services/jobs.js
+++ b/lib/cluster/services/jobs.js
@@ -340,11 +340,18 @@ module.exports = function(context, cluster_service) {
     }
 
     // Updates the job but does not automatically start it.
-    function updateJob(job_id, job) {
-        return job_store.update(job_id, job)
+    function updateJob(job_id, jobUpdates) {
+        return getJob(job_id)
+            .then(function(job_spec) {
+                var updatedJob = _.assign({}, job_spec, jobUpdates);
+                return _validateJob(updatedJob);
+            })
+            .then(function(validJob) {
+                return job_store.update(job_id, validJob);
+            })
             .catch(function(err) {
                 var errMsg = parseError(err);
-                logger.error(`could not updateJob`, errMsg)
+                logger.error(`could not updateJob`, errMsg);
             });
     }