diff --git a/fastapi/encoders.py b/fastapi/encoders.py
index da3f8a8a3..373dc2c0f 100644
--- a/fastapi/encoders.py
+++ b/fastapi/encoders.py
@@ -123,7 +123,9 @@ def generate_encoders_by_class_tuples(
     return encoders_by_class_tuples
 
 
-encoders_by_class_tuples = generate_encoders_by_class_tuples(ENCODERS_BY_TYPE | encoders_by_extra_type)
+encoders_by_class_tuples = generate_encoders_by_class_tuples(
+    ENCODERS_BY_TYPE | encoders_by_extra_type
+)
 
 
 def jsonable_encoder(