diff --git a/fastapi/applications.py b/fastapi/applications.py
index ffe9da358..d3edcc880 100644
--- a/fastapi/applications.py
+++ b/fastapi/applications.py
@@ -1019,7 +1019,7 @@ class FastAPI(Starlette):
                     oauth2_redirect_url = root_path + oauth2_redirect_url
                 return get_swagger_ui_html(
                     openapi_url=openapi_url,
-                    title=self.title + " - Swagger UI",
+                    title=f"{self.title} - Swagger UI",
                     oauth2_redirect_url=oauth2_redirect_url,
                     init_oauth=self.swagger_ui_init_oauth,
                     swagger_ui_parameters=self.swagger_ui_parameters,
@@ -1043,7 +1043,7 @@ class FastAPI(Starlette):
                 root_path = req.scope.get("root_path", "").rstrip("/")
                 openapi_url = root_path + self.openapi_url
                 return get_redoc_html(
-                    openapi_url=openapi_url, title=self.title + " - ReDoc"
+                    openapi_url=openapi_url, title=f"{self.title} - ReDoc"
                 )
 
             self.add_route(self.redoc_url, redoc_html, include_in_schema=False)