diff --git a/src/openrct2-ui/windows/LoadSave.cpp b/src/openrct2-ui/windows/LoadSave.cpp
index 659939f68e..bc46faf9c1 100644
--- a/src/openrct2-ui/windows/LoadSave.cpp
+++ b/src/openrct2-ui/windows/LoadSave.cpp
@@ -1087,7 +1087,8 @@ static void WindowLoadsaveSelect(rct_window* w, const char* path)
         {
             SetAndSaveConfigPath(gConfigGeneral.last_save_track_directory, pathBuffer);
 
-            path_set_extension(pathBuffer, "td6", sizeof(pathBuffer));
+            const auto withExtension = Path::WithExtension(pathBuffer, "td6");
+            String::Set(pathBuffer, sizeof(pathBuffer), withExtension.c_str());
 
             RCT2::T6Exporter t6Export{ _trackDesign };
 
diff --git a/src/openrct2/core/Path.cpp b/src/openrct2/core/Path.cpp
index 303e45cef0..4814ad7574 100644
--- a/src/openrct2/core/Path.cpp
+++ b/src/openrct2/core/Path.cpp
@@ -80,6 +80,11 @@ namespace Path
         return u8path(path).extension().u8string();
     }
 
+    u8string WithExtension(u8string_view path, u8string_view newExtension)
+    {
+        return u8path(path).replace_extension(u8path(newExtension)).u8string();
+    }
+
     u8string GetAbsolute(u8string_view relative)
     {
         std::error_code ec;
diff --git a/src/openrct2/core/Path.hpp b/src/openrct2/core/Path.hpp
index d3179ae50b..b32ab85d27 100644
--- a/src/openrct2/core/Path.hpp
+++ b/src/openrct2/core/Path.hpp
@@ -30,6 +30,7 @@ namespace Path
     u8string GetFileName(u8string_view origPath);
     u8string GetFileNameWithoutExtension(u8string_view path);
     u8string GetExtension(u8string_view path);
+    u8string WithExtension(u8string_view path, u8string_view newExtension);
     u8string GetAbsolute(u8string_view relative);
     bool Equals(u8string_view a, u8string_view b);
 
diff --git a/src/openrct2/util/Util.cpp b/src/openrct2/util/Util.cpp
index bbebe2170e..1b4594bc79 100644
--- a/src/openrct2/util/Util.cpp
+++ b/src/openrct2/util/Util.cpp
@@ -101,15 +101,6 @@ static const char* path_get_filename(const utf8* path)
     return filename;
 }
 
-void path_set_extension(utf8* path, const utf8* newExtension, size_t size)
-{
-    // Remove existing extension (check first if there is one)
-    if (!Path::GetExtension(path).empty())
-        path_remove_extension(path);
-    // Append new extension
-    path_append_extension(path, newExtension, size);
-}
-
 void path_append_extension(utf8* path, const utf8* newExtension, size_t size)
 {
     // Skip to the dot if the extension starts with a pattern (starts with "*.")
diff --git a/src/openrct2/util/Util.h b/src/openrct2/util/Util.h
index e62f285baf..327a282716 100644
--- a/src/openrct2/util/Util.h
+++ b/src/openrct2/util/Util.h
@@ -26,7 +26,6 @@ int32_t mph_to_dmps(int32_t mph);
 bool filename_valid_characters(const utf8* filename);
 
 char* path_get_directory(const utf8* path);
-void path_set_extension(utf8* path, const utf8* newExtension, size_t size);
 void path_append_extension(utf8* path, const utf8* newExtension, size_t size);
 void path_remove_extension(utf8* path);
 void path_end_with_separator(utf8* path, size_t size);