diff --git a/example/synchronous_resnet/resnet_worker.py b/example/synchronous_resnet/resnet_worker.py
index 56a4960..ed56c99 100644
--- a/example/synchronous_resnet/resnet_worker.py
+++ b/example/synchronous_resnet/resnet_worker.py
@@ -444,6 +444,7 @@ def pred_error(f_pred, data, iterator):
         x = [data[0][t] for t in valid_index]
         y = [data[1][t] for t in valid_index]
         valid_err += f_pred(x, y)
+        f_pred.sync_shared()
         i += 1
 
     return valid_err / i
@@ -524,7 +525,9 @@ def train_iter():
             x, y = next(train_it)
             func_time = time.time()
             cost = f_grad_shared(x, y)
+            cost.sync_shared()
             f_update(lrate)
+            f_update.sync_shared()
             print("Func call time", time.time() - func_time)
             overhead_time = time.time()
             asgd()