diff --git a/apps/gpu/LBM/MusselOyster/MusselOyster.cpp b/apps/gpu/LBM/MusselOyster/MusselOyster.cpp
index 03503b31ce77f0f7762b982c918f71a0b5ed1884..b4710bd81b9b6c0d6c2a1b2f1a3e4f860940d0dd 100644
--- a/apps/gpu/LBM/MusselOyster/MusselOyster.cpp
+++ b/apps/gpu/LBM/MusselOyster/MusselOyster.cpp
@@ -404,7 +404,7 @@ void multipleLevel(const std::string& configPath)
             // std::to_string(generatePart) + "/grid/"); gridBuilder->writeArrows(outPath + bivalveType + "/" +
             // std::to_string(generatePart) + " /arrow");
 
-            SimulationFileWriter::write(gridPath + "/" + std::to_string(generatePart) + "/", gridBuilder,
+            SimulationFileWriter::write(gridPath + std::to_string(generatePart) + "/", gridBuilder,
                                         FILEFORMAT::BINARY);
         } else {