diff --git a/kittens/diff/main.py b/kittens/diff/main.py
index 31eea9ff7..e9e8d4eea 100644
--- a/kittens/diff/main.py
+++ b/kittens/diff/main.py
@@ -314,6 +314,8 @@ elif __name__ == '__doc__':
     cd['options'] = OPTIONS
     cd['help_text'] = help_text
     cd['short_desc'] = 'Pretty, side-by-side diffing of files and images'
-    cd['args_completion'] = CompletionSpec.from_string('type:file mime:text/* mime:image/* group:"Text and image files"')
+    cd['args_completion'] = CompletionSpec.from_string(
+            'type:file mime:text/* mime:image/* ext:sh ext:json ext:yaml ext:toml ext:lua ext:rss ext:xml ext:xhtml'
+            ' group:"Text and image files"')
 elif __name__ == '__conf__':
     sys.options_definition = definition  # type: ignore