diff --git a/package.json b/package.json
index 3974e90..224e2d4 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,12 @@
   },
   "xo": {
     "space": 2,
-    "envs": ["node", "mocha"]
+    "overrides": [
+      {
+        "files": "test/*.js",
+        "envs": ["node", "mocha"]
+      }
+    ]
   },
   "keywords": [
     "doc",