diff --git a/src/flask/signals.py b/src/flask/signals.py
index 2c6d6469..187e023a 100644
--- a/src/flask/signals.py
+++ b/src/flask/signals.py
@@ -27,8 +27,7 @@ except ImportError:
 
         def _fail(self, *args: t.Any, **kwargs: t.Any) -> t.Any:
             raise RuntimeError(
-                "Signalling support is unavailable because the blinker"
-                " library is not installed."
+                """Signalling support is unavailable because the blinker library is not installed."""
             ) from None
 
         connect = connect_via = connected_to = temporarily_connected_to = _fail