diff --git a/README.md b/README.md
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+++ b/README.md
@@ -1,5 +1,7 @@
 # fluent-plugin-flatten-hash, a plugin for [Fluentd](http://fluentd.org)
 
+[![Build Status](https://travis-ci.org/kazegusuri/fluent-plugin-flatten-hash.svg?branch=master)](https://travis-ci.org/kazegusuri/fluent-plugin-flatten-hash)  
+
 A fluentd plugin to flatten nested hash structure as a flat record with unique keys generated by its path for each values.
 
 ## Installation