diff --git a/onnxruntime/core/framework/tensorprotoutils.cc b/onnxruntime/core/framework/tensorprotoutils.cc
index dfff5d934b925..d770cfcbcfd7f 100644
--- a/onnxruntime/core/framework/tensorprotoutils.cc
+++ b/onnxruntime/core/framework/tensorprotoutils.cc
@@ -184,7 +184,7 @@ T resolve_external_data_location(
     }
 #if defined(__APPLE__) && TARGET_OS_IPHONE
     // workaround 'wstring' is unavailable: introduced in iOS 13.0
-    auto relative_path = ToWideString(file_path.lexically_normal().make_preferred().u8string());
+    auto relative_path = ToWideString(file_path.lexically_normal().make_preferred().string());
 #else
     auto relative_path = file_path.lexically_normal().make_preferred().wstring();
 #endif