diff --git a/.gitignore b/.gitignore
index 0cc9f67..7e446fc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 node_modules
 yarn.lock
 !/test/fixtures/**/node_modules
+coverage
diff --git a/package.json b/package.json
index 5a2247d..03db5b0 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,7 @@
 		"node": ">=18.19"
 	},
 	"scripts": {
-		"test": "xo && ava && tsc ./source/index.d.ts"
+		"test": "xo && c8 ava && tsc ./source/index.d.ts"
 	},
 	"files": [
 		"source/**/*.js",
@@ -48,6 +48,7 @@
 	],
 	"devDependencies": {
 		"ava": "^6.1.3",
+		"c8": "^10.1.2",
 		"get-node": "^15.0.1",
 		"path-key": "^4.0.0",
 		"tempy": "^3.1.0",
diff --git a/readme.md b/readme.md
index 87fcedb..329d665 100644
--- a/readme.md
+++ b/readme.md
@@ -4,6 +4,7 @@
 
 [![Install size](https://packagephobia.com/badge?p=nano-spawn)](https://packagephobia.com/result?p=nano-spawn)
 ![npm package minzipped size](https://img.shields.io/bundlejs/size/nano-spawn)
+![Test coverage](https://img.shields.io/badge/coverage-100%25-green)
 <!-- [![Downloads](https://img.shields.io/npm/dm/nano-spawn.svg)](https://npmjs.com/nano-spawn) -->
 <!-- ![Dependents](https://img.shields.io/librariesio/dependents/npm/nano-spawn) -->