diff --git a/repertory/librepertory/src/file_manager/open_file.cpp b/repertory/librepertory/src/file_manager/open_file.cpp
index 3e42f099..833a47ae 100644
--- a/repertory/librepertory/src/file_manager/open_file.cpp
+++ b/repertory/librepertory/src/file_manager/open_file.cpp
@@ -65,7 +65,8 @@ open_file::open_file(std::uint64_t chunk_size, std::uint8_t chunk_timeout,
     : open_file_base(chunk_size, chunk_timeout, fsi, open_data, provider),
       mgr_(mgr) {
   if (fsi_.directory && read_state.has_value()) {
-    throw startup_exception("cannot resume a directory|" + fsi.api_path);
+    throw startup_exception(
+        fmt::format("cannot resume a directory|sp|", fsi.api_path));
   }
 
   if (fsi.directory) {