diff --git a/logprep/connector/s3/output.py b/logprep/connector/s3/output.py
index adb3b3edc..e7136a25b 100644
--- a/logprep/connector/s3/output.py
+++ b/logprep/connector/s3/output.py
@@ -112,6 +112,9 @@ class Config(Output.Config):
         )
         """The input callback is called after the maximum backlog size has been reached 
         if this is set to True (optional)"""
+        flush_timeout: Optional[int] = field(validator=validators.instance_of(int), default=60)
+        """(Optional) Timout after :code:`message_backlog` is flushed if 
+        :code:`message_backlog_size` is not reached."""
 
     @define(kw_only=True)
     class Metrics(Output.Metrics):
@@ -141,6 +144,7 @@ def __init__(self, name: str, configuration: "S3Output.Config", logger: Logger):
         self._base_prefix = f"{self._config.base_prefix}/" if self._config.base_prefix else ""
         self._s3_resource = None
         self._setup_s3_resource()
+        self._schedule_task(task=self._write_backlog, seconds=self._config.flush_timeout)
 
     def _setup_s3_resource(self):
         session = boto3.Session(
diff --git a/tests/unit/connector/test_s3_output.py b/tests/unit/connector/test_s3_output.py
index 301e34582..d718cd7b3 100644
--- a/tests/unit/connector/test_s3_output.py
+++ b/tests/unit/connector/test_s3_output.py
@@ -270,6 +270,7 @@ def test_message_backlog_is_not_written_if_message_backlog_size_not_reached(self
     def test_store_failed_counts_failed_events(self):
         self.object._write_backlog = mock.MagicMock()
         super().test_store_failed_counts_failed_events()
+        self.object._scheduler.jobs = []  # If I don't do this I poison the scheduler for all subsequent tests (wtf)
 
     @staticmethod
     def _calculate_backlog_size(s3_output):