diff --git a/src/flask/scaffold.py b/src/flask/scaffold.py
index 75776f4f..fa78b8e2 100644
--- a/src/flask/scaffold.py
+++ b/src/flask/scaffold.py
@@ -364,7 +364,7 @@ class Scaffold:
         if mode not in {"r", "rt", "rb"}:
             raise ValueError("Resources can only be opened for reading.")
 
-        return open(os.path.join(self.root_path, resource), mode, encoding="utf-8")
+        return open(os.path.join(self.root_path, resource), mode)
 
     def _method_route(
         self,