diff --git a/slow/slow.py b/slow/slow.py
index a6a784d..0d50ffa 100644
--- a/slow/slow.py
+++ b/slow/slow.py
@@ -85,9 +85,7 @@ class App:
         iter = PR.finditer(temp)
         for m in iter:
             name = m[1]
-            re_temp = re.sub(
-                m[0], r"(?P<" + name + r">[a-zA-Z0-9\-._~:%&=]+)", re_temp
-            )
+            re_temp = re.sub(m[0], r"(?P<" + name + r">[a-zA-Z0-9\-._~:%&=]+)", re_temp)
         return re.compile(re_temp)
 
     def _serve(