diff --git a/.c8rc.json b/.c8rc.json
index 9a0ef4f2..effaa95f 100644
--- a/.c8rc.json
+++ b/.c8rc.json
@@ -1,5 +1,5 @@
 {
-  "include": [
-    "lib/*.js"
-  ]
+  "all": true,
+  "src": ["./src"],
+  "include": ["lib/**"]
 }
diff --git a/package.json b/package.json
index b11989b5..02e12b7a 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
     "precommit": "lint-staged",
     "prepublish": "yarn run clean && yarn run build",
     "preversion": "yarn run test",
-    "test": "yarn run lint && yarn run build && c8 yarn run test-only",
+    "test": "yarn run lint && yarn run build --source-maps && c8 yarn run test-only",
     "test-only": "ava"
   },
   "repository": {