diff --git a/package.json b/package.json
index be32ea5..d0f18f6 100644
--- a/package.json
+++ b/package.json
@@ -10,8 +10,8 @@
   },
   "scripts": {
     "lint": "eslint src",
-    "test": "ava --require babel-register --source='*.test.js' --tap=${CI-false} | $(if [ -z ${CI:-} ]; then echo 'tail'; else tap-xunit > $CIRCLE_TEST_REPORTS/ava/ava.xml; fi;)",
-    "tdd": "ava --require babel-register --source='*.test.js' --watch",
+    "test": "ava --require babel-register --source='src/**/*.js' --source='!build/**/*' --tap=${CI-false} src/**/*.test.js | $(if [ -z ${CI:-} ]; then echo 'tail'; else tap-xunit > $CIRCLE_TEST_REPORTS/ava/ava.xml; fi;)",
+    "tdd": "ava --require babel-register --source='src/**/*.js' --source='!build/**/*' --watch src/**/*.test.js",
     "build": "scripty",
     "watch": "scripty"
   },
@@ -31,6 +31,7 @@
     "babel-plugin-transform-decorators-legacy": "^1.3.4",
     "babel-plugin-transform-es2015-modules-commonjs": "^6.14.0",
     "babel-preset-stage-1": "^6.13.0",
+    "babel-register": "^6.14.0",
     "eslint": "^3.4.0",
     "eslint-config-pichak": "^1.1.2",
     "eslint-plugin-ava": "^3.0.0",