diff --git a/package.json b/package.json
index 27764875..92ee8ab8 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
     "typescript": "^1.8.7"
   },
   "dependencies": {
-    "pxt-core": "0.5.18",
+    "pxt-core": "0.5.21",
     "less": "^2.6.0",
     "semantic-ui-less": "^2.2.4"
   }