diff --git a/README.md b/README.md
index f9da4e4..cefeadc 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 [![GoDoc](https://godoc.org/github.com/alexflint/go-arg?status.svg)](https://godoc.org/github.com/alexflint/go-arg)
 [![Build Status](https://github.com/alexflint/go-arg/workflows/Go/badge.svg)](https://github.com/alexflint/go-arg/actions)
 [![GolangCI](https://golangci.com/badges/github.com/alexflint/go-arg.svg)](https://golangci.com/r/github.com/alexflint/go-arg)
+-[![Coverage](https://coveralls.io/repos/alexflint/go-arg/badge.svg?branch=master&service=github)](https://coveralls.io/github/alexflint/go-arg?branch=master)
 [![Report Card](https://goreportcard.com/badge/github.com/alexflint/go-arg)](https://goreportcard.com/badge/github.com/alexflint/go-arg)