diff --git a/scripts/build/core-package.json.template b/scripts/build/core-package.json.template
index a722389b7..b6b5e6843 100644
--- a/scripts/build/core-package.json.template
+++ b/scripts/build/core-package.json.template
@@ -7,7 +7,7 @@
   "author": "ionic",
   "license": "MIT",
   "peerDependencies": {
-    "rxjs": "^5.0.1"
+    "rxjs": "5.0.0-beta.12"
   },
   "repository": {
     "type": "git",