diff --git a/pxt.json b/pxt.json
index 8a27210..1851109 100644
--- a/pxt.json
+++ b/pxt.json
@@ -5,7 +5,7 @@
     "dependencies": {
         "core": "*",
         "radio": "*"
-        "pxt-serial-rb": "github:hhf42/pxt-serial-rb",
+        "pxt-serial-rb": "github:hhf42/pxt-serial-rb"
     },
     "files": [
         "README.md",