diff --git a/libsrc/core/utils.cpp b/libsrc/core/utils.cpp
index 28247492..b0ad1e98 100644
--- a/libsrc/core/utils.cpp
+++ b/libsrc/core/utils.cpp
@@ -118,7 +118,7 @@ namespace ngcore
       auto path = std::filesystem::temp_directory_path();
       std::string filename = ".temp_netgen_file_"+ToString(counter++)+"_"+ToString(GetTimeCounter());
       path.append(filename);
-      return path;
+      return path.string();
   }
 
 } // namespace ngcore