diff --git a/rebound/simulation.py b/rebound/simulation.py
index 9fc607933..32b4704d1 100644
--- a/rebound/simulation.py
+++ b/rebound/simulation.py
@@ -1417,6 +1417,7 @@ def integrator_synchronize(self):
         Call this function if safe-mode is disabled and you need to synchronize particle positions and velocities between timesteps.
         """
         clibrebound.reb_simulation_synchronize(byref(self))
+        self.process_messages()
     
     def tree_update(self):
         """