diff --git a/build/tasks/spec-task.coffee b/build/tasks/spec-task.coffee
index abba219e5..2f4c6e277 100644
--- a/build/tasks/spec-task.coffee
+++ b/build/tasks/spec-task.coffee
@@ -158,4 +158,4 @@ module.exports = (grunt) ->
       if process.platform is 'win32' and process.env.JANKY_SHA1
         done()
       else
-        done(not coreSpecFailed and failedPackages.length is 0)
+        done(not coreSpecFailed and failedPackages?.length is 0)