diff --git a/quamash/_windows.py b/quamash/_windows.py
index c94ef46..7392974 100644
--- a/quamash/_windows.py
+++ b/quamash/_windows.py
@@ -41,7 +41,7 @@ def _process_events(self, events):
 				self._logger.debug('Invoking event callback {}'.format(callback))
 				value = callback(transferred, key, ov)
 			except OSError:
-				self._logger.warning('Event callback failed', exc_info=sys.exc_info())
+				self._logger.debug('Event callback failed', exc_info=sys.exc_info())
 			else:
 				f.set_result(value)