diff --git a/.eslintignore b/.eslintignore
new file mode 100644
index 0000000..404abb2
--- /dev/null
+++ b/.eslintignore
@@ -0,0 +1 @@
+coverage/
diff --git a/.nycrc b/.nycrc
new file mode 100644
index 0000000..1826526
--- /dev/null
+++ b/.nycrc
@@ -0,0 +1,13 @@
+{
+	"all": true,
+	"check-coverage": false,
+	"reporter": ["text-summary", "text", "html", "json"],
+	"lines": 86,
+	"statements": 85.93,
+	"functions": 82.43,
+	"branches": 76.06,
+	"exclude": [
+		"coverage",
+		"test"
+	]
+}
diff --git a/package.json b/package.json
index 4379da1..394c109 100644
--- a/package.json
+++ b/package.json
@@ -13,11 +13,12 @@
 	},
 	"scripts": {
 		"prepublish": "safe-publish-latest",
-		"lint": "eslint .",
+		"lint": "eslint --ext=js,mjs .",
 		"pretest": "npm run lint",
-		"tests-only": "node test",
-		"test": "npm run tests-only",
-		"posttest": "npx aud --production",
+		"tests-only": "nyc tape 'test/**/*.js'",
+		"test:harmony": "nyc node --harmony --es-staging test",
+		"test": "npm run tests-only && npm run test:harmony",
+		"posttest": "aud --production",
 		"version": "auto-changelog && git add CHANGELOG.md",
 		"postversion": "auto-changelog && git add CHANGELOG.md && git commit --no-edit --amend && git tag -f \"v$(node -e \"console.log(require('./package.json').version)\")\""
 	},
@@ -53,6 +54,7 @@
 		"aud": "^1.1.1",
 		"auto-changelog": "^2.0.0",
 		"eslint": "^6.8.0",
+		"nyc": "^10.3.2",
 		"safe-publish-latest": "^1.1.4",
 		"tape": "^5.0.0-next.5"
 	},