diff --git a/eventkit/ops/op.py b/eventkit/ops/op.py
index 61f9dbe..978afac 100644
--- a/eventkit/ops/op.py
+++ b/eventkit/ops/op.py
@@ -53,7 +53,8 @@ def _connect_from(self, source: Event):
             source.connect(
                 self.on_source,
                 self.on_source_error,
-                self.on_source_done)
+                self.on_source_done,
+                keep_ref=True)
 
     def _disconnect_from(self, source: Event):
         source.disconnect(