diff --git a/docs/helpers.py b/docs/helpers.py
index 57d45c7..9b5fee6 100644
--- a/docs/helpers.py
+++ b/docs/helpers.py
@@ -23,7 +23,7 @@ def append_file(self, file_path: str, file_name: Optional[str] = None):
     def append_shinylive_chunk(
         self,
         files: list[str] | str,
-        language: str = "py",
+        language: Literal["auto", "py", "r"] = "auto",
         **kwargs,
     ):
         if isinstance(files, str):
@@ -32,6 +32,9 @@ def append_shinylive_chunk(
         else:
             app_file = files.pop(0)
 
+        if language == "auto":
+            language = "py" if app_file.endswith(".py") else "r"
+
         app = ShinyliveApp.from_local(app_file, files, language)
 
         self.append(app.to_chunk(**kwargs))