diff --git a/jest-unit.json b/jest-unit.json
index bc91f0f6..19685d46 100644
--- a/jest-unit.json
+++ b/jest-unit.json
@@ -13,6 +13,7 @@
     "object-assign",
     "underscore",
     "source-map-support",
-    "<rootDir>/node_modules/.*JSONStream"
+    "<rootDir>/node_modules/.*JSONStream",
+    "<rootDir>/node_modules/core-js"
   ]
 }