Update backoff/_wait_gen.py

hauntsaninja · web-flow · commit 52aef92a1d44 · 2022-10-03T15:53:09.000-07:00
diff --git a/backoff/_wait_gen.py b/backoff/_wait_gen.py
@@ -8,7 +8,7 @@ def expo(
     base: float = 2,
     factor: float = 1,
     max_value: Optional[float] = None
-) -> Generator[float, Any, None]:
+) -> Generator[Optional[float], Any, None]:
 
     """Generator for exponential decay.
 
