diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index de6aad48..22f370b3 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -654,6 +654,7 @@ Ruby:
   - .gemspec
   - .irbrc
   - .thor
+  - .rbuild
   filenames:
   - Capfile
   - Rakefile