diff --git a/fastapi/utils.py b/fastapi/utils.py
index f8463dda24675..0019c21532b48 100644
--- a/fastapi/utils.py
+++ b/fastapi/utils.py
@@ -173,17 +173,17 @@ def generate_operation_id_for_path(
         DeprecationWarning,
         stacklevel=2,
     )
-    operation_id = name + path
+    operation_id = f"{name}{path}"
     operation_id = re.sub(r"\W", "_", operation_id)
-    operation_id = operation_id + "_" + method.lower()
+    operation_id = f"{operation_id}_{method.lower()}"
     return operation_id
 
 
 def generate_unique_id(route: "APIRoute") -> str:
-    operation_id = route.name + route.path_format
+    operation_id = f"{route.name}{route.path_format}"
     operation_id = re.sub(r"\W", "_", operation_id)
     assert route.methods
-    operation_id = operation_id + "_" + list(route.methods)[0].lower()
+    operation_id = f"{operation_id}_{list(route.methods)[0].lower()}"
     return operation_id