diff --git a/src/components/ChallengeEditor/index.js b/src/components/ChallengeEditor/index.js
index 9521fa37..df9ebc2c 100644
--- a/src/components/ChallengeEditor/index.js
+++ b/src/components/ChallengeEditor/index.js
@@ -823,9 +823,10 @@ class ChallengeEditor extends Component {
       if (newChallenge.phases[phaseIndex]['name'] === 'Submission') {
         newChallenge.phases[phaseIndex]['scheduledStartDate'] =
           newChallenge.phases[phaseIndex - 1]['scheduledStartDate']
-        newChallenge.phases[phaseIndex]['duration'] =
-          _.max(newChallenge.phases[phaseIndex - 1]['duration'],
-            newChallenge.phases[phaseIndex]['duration'])
+        newChallenge.phases[phaseIndex]['duration'] = _.max([
+          newChallenge.phases[phaseIndex - 1]['duration'],
+          newChallenge.phases[phaseIndex]['duration']
+        ])
       } else {
         newChallenge.phases[phaseIndex]['scheduledStartDate'] =
           newChallenge.phases[phaseIndex - 1]['scheduledEndDate']