diff --git a/tests/unit/.eslintrc b/tests/unit/.eslintrc
index c934038f..4443ecbc 100644
--- a/tests/unit/.eslintrc
+++ b/tests/unit/.eslintrc
@@ -3,8 +3,8 @@
     "mocha": true
   },
   "globals": {
-    "expect": true,
-    "sinon": true
+    "expect": "readonly",
+    "sinon": "readonly"
   },
   "rules": {
     "no-unused-expressions": "off"