diff --git a/package.json b/package.json
index fc18203dca5e7..5c45aa0d73303 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
     "node-ensure": "^0.0.0",
     "rimraf": "^2.6.2",
     "streamqueue": "^1.1.2",
-    "systemjs": "^0.21.0",
+    "systemjs": "0.21.0",
     "systemjs-plugin-babel": "^0.0.25",
     "ttest": "^1.1.0",
     "typogr": "^0.6.7",