diff --git a/areal/trainer/rl_trainer.py b/areal/trainer/rl_trainer.py
index 73b98c21f..9640cc611 100644
--- a/areal/trainer/rl_trainer.py
+++ b/areal/trainer/rl_trainer.py
@@ -1115,7 +1115,8 @@ def _save_hf(self, epoch: int, epoch_step: int, global_step: int):
         # Async mode: synchronization handled by AsyncCheckpointManager
         if not self.saver.is_async:
             dist.barrier(group=self.actor.cpu_group)
-            current_platform.synchronize()
+            if not is_single_controller():
+                current_platform.synchronize()
 
     def _save_recover_checkpoint(self, epoch: int, epoch_step: int, global_step: int):
         # Save recoverable checkpoints
@@ -1140,7 +1141,8 @@ def _save_recover_checkpoint(self, epoch: int, epoch_step: int, global_step: int
         )
 
         dist.barrier(group=self.actor.cpu_group)
-        current_platform.synchronize()
+        if not is_single_controller():
+            current_platform.synchronize()
 
     def _evaluate_fn(
         self,
@@ -1162,7 +1164,8 @@ def _evaluate_fn(
             self.eval_rollout.wait(cnt, timeout=None)
 
         dist.barrier(group=self.actor.cpu_group)
-        current_platform.synchronize()
+        if not is_single_controller():
+            current_platform.synchronize()
 
     def _evaluate(
         self,
@@ -1189,7 +1192,8 @@ def _evaluate(
             global_step,
         )
         dist.barrier(group=self.actor.cpu_group)
-        current_platform.synchronize()
+        if not is_single_controller():
+            current_platform.synchronize()
 
     def _export_and_commit_stats(self, epoch: int, epoch_step: int, global_step: int):
         # Upload statistics to the logger (e.g., wandb)
@@ -1200,7 +1204,8 @@ def _export_and_commit_stats(self, epoch: int, epoch_step: int, global_step: int
         self.stats_logger.commit(epoch, epoch_step, global_step, stats)
 
         dist.barrier(group=self.actor.cpu_group)
-        current_platform.synchronize()
+        if not is_single_controller():
+            current_platform.synchronize()
 
     def _validate_cfg(self):
         """validate config for incompatible settings before weight initialization, to avoid wasted resources on spawning workers and loading models."""