diff --git a/GPUSimulators/HLL2.py b/GPUSimulators/HLL2.py
index b248eb2..e9b1313 100644
--- a/GPUSimulators/HLL2.py
+++ b/GPUSimulators/HLL2.py
@@ -177,9 +177,10 @@ class HLL2 (Simulator.BaseSimulator):
                         )
                     )
                 )
+
+        hip_check(hip.hipDeviceSynchronize())    
         self.u0, self.u1 = self.u1, self.u0
     
-        hip_check(hip.hipDeviceSynchronize())
         hip_check(hip.hipModuleUnload(module))
 
         hip_check(hip.hipFree(cfl_data))