diff --git a/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py b/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py
index 2f5a31e4..39aaf1c1 100644
--- a/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py
+++ b/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py
@@ -124,7 +124,7 @@ def _wrap_callback_errors(
     """
     try:
         callback(message)
-    except Exception as exc:
+    except BaseException as exc:
         # Note: the likelihood of this failing is extremely low. This just adds
         # a message to a queue, so if this doesn't work the world is in an
         # unrecoverable state and this thread should just bail.