diff --git a/src/gpu/VirtualFluids_GPU/Calculation/UpdateGrid27.cpp b/src/gpu/VirtualFluids_GPU/Calculation/UpdateGrid27.cpp
index 3aee6c46b5cea7e810ad957f763745b0731d00e4..6064f37cf76ec74667ec13f9bf7593eff98ed11c 100644
--- a/src/gpu/VirtualFluids_GPU/Calculation/UpdateGrid27.cpp
+++ b/src/gpu/VirtualFluids_GPU/Calculation/UpdateGrid27.cpp
@@ -81,6 +81,7 @@ void UpdateGrid27::refinementAndExchange_streams(int level)
     coarseToFineWithStream(para.get(), level, para->getParD(level)->intCFBorder.ICellCFC,
                            para->getParD(level)->intCFBorder.ICellCFF, para->getParD(level)->intCFBorder.kCF, para->getParD(level)->offCF,
                            borderStreamIndex);
+    cudaDeviceSynchronize(); 
 }
 
 void UpdateGrid27::refinementAndExchange_noStreams_onlyExchangeInterface(int level)