diff --git a/package.json b/package.json
index b0f0d26c56..8ed7ef2558 100644
--- a/package.json
+++ b/package.json
@@ -74,7 +74,7 @@
     "isomorphic-fetch": "^2.2.1",
     "linkifyjs": "^2.1.3",
     "lodash": "^4.13.1",
-    "lolex": "^2.3.2",
+    "lolex": "2.3.2",
     "matrix-js-sdk": "0.10.1",
     "optimist": "^0.6.1",
     "pako": "^1.0.5",