diff --git a/README.md b/README.md
index ff160f0..98bfd66 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 [![Build Status,](https://img.shields.io/travis/jsmaniac/tr-immutable/master.svg)](https://travis-ci.org/jsmaniac/tr-immutable)
-[![Coverage Status,](https://img.shields.io/codecov/c/github/jsmaniac/tr-immutable/master.svg)](https://codecov.io/gh/jsmaniac/tr-immutable/branch/master)
+[![Coverage Status,](https://img.shields.io/codecov/c/github/jsmaniac/tr-immutable/main.svg)](https://codecov.io/gh/jsmaniac/tr-immutable/branch/main)
 [![Build Stats,](https://img.shields.io/badge/build-stats-blue.svg)](http://jsmaniac.github.io/travis-stats/#jsmaniac/tr-immutable)
 [![Online Documentation.](https://img.shields.io/badge/docs-online-blue.svg)](http://docs.racket-lang.org/tr-immutable/)