diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 9286620b..f72c03a4 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1203,6 +1203,8 @@ Shell:
   primary_extension: .sh
   extensions:
   - .tmux
+  filenames:
+  - Dockerfile
 
 Slash:
   type: programming