Display coverage data for master branch
diff --git a/README.md b/README.md
index 1378f29..a477973 100644
--- a/README.md
+++ b/README.md
@@ -44,7 +44,7 @@
 ===================
 
 [![Build Status](https://travis-ci.org/apache/commons-cli.svg?branch=master)](https://travis-ci.org/apache/commons-cli)
-[![Coverage Status](https://coveralls.io/repos/github/apache/commons-cli/badge.svg?branch=trunk)](https://coveralls.io/github/apache/commons-cli?branch=trunk)
+[![Coverage Status](https://coveralls.io/repos/github/apache/commons-cli/badge.svg?branch=master)](https://coveralls.io/github/apache/commons-cli?branch=master)
 
 Apache Commons CLI provides a simple API for presenting, processing and validating a command line interface.