diff --git a/package.json b/package.json
index fee51d6f06..6040050e39 100644
--- a/package.json
+++ b/package.json
@@ -44,11 +44,11 @@
     "es6-symbol": "0.1.1",
     "regexpu": "0.3.0",
     "source-map": "0.1.40",
-    "regenerator-6to5": "https://github.com/sebmck/regenerator-6to5/archive/master.tar.gz",
+    "regenerator-6to5": "https://github.com/sebmck/regenerator-6to5/archive/b7bc53e1a655879974aad53a8ceb93a70efaa08d.tar.gz",
     "chokidar": "0.10.0",
     "source-map-support": "0.2.7",
     "esutils": "1.1.4",
-    "acorn-6to5": "https://github.com/sebmck/acorn-6to5/archive/master.tar.gz",
+    "acorn-6to5": "https://github.com/sebmck/acorn-6to5/archive/f5110383517eef0bea78c2da2a1fb01fbed74e4e.tar.gz",
     "estraverse": "^1.7.0",
     "v8-argv": "^0.2.0"
   },