diff --git a/server/boot/challenge.js b/server/boot/challenge.js
index 239d21d4d0..4ce4937e67 100644
--- a/server/boot/challenge.js
+++ b/server/boot/challenge.js
@@ -519,7 +519,7 @@ module.exports = function(app) {
         const lastCompletedBlock = _.findLast(blocks, (block) => {
           return block.completed === 100;
         });
-        lastCompleted = lastCompletedBlock.name;
+        lastCompleted = lastCompleted && lastCompletedBlock.name || null;
       });
 
     Observable.combineLatest(