diff --git a/engine/migrations/migration_helper.cc b/engine/migrations/migration_helper.cc
index 28c560f9e..42cc8d453 100644
--- a/engine/migrations/migration_helper.cc
+++ b/engine/migrations/migration_helper.cc
@@ -7,15 +7,10 @@ cpp::result<bool, std::string> MigrationHelper::BackupDatabase(
   try {
     SQLite::Database src_db(src_db_path, SQLite::OPEN_READONLY);
     sqlite3* backup_db;
-#if defined(_WIN32)
-    if (sqlite3_open16(backup_db_path.c_str(), &backup_db) != SQLITE_OK) {
-      throw std::runtime_error("Failed to open backup database");
-    }
-#else
+    
     if (sqlite3_open(backup_db_path.c_str(), &backup_db) != SQLITE_OK) {
       throw std::runtime_error("Failed to open backup database");
     }
-#endif
 
     sqlite3_backup* backup =
         sqlite3_backup_init(backup_db, "main", src_db.getHandle(), "main");
diff --git a/engine/migrations/migration_manager.cc b/engine/migrations/migration_manager.cc
index f4b4f8046..2c2b6ddfd 100644
--- a/engine/migrations/migration_manager.cc
+++ b/engine/migrations/migration_manager.cc
@@ -4,6 +4,7 @@
 #include "schema_version.h"
 #include "utils/file_manager_utils.h"
 #include "utils/scope_exit.h"
+#include "utils/widechar_conv.h"
 
 namespace cortex::migr {
 
@@ -40,7 +41,13 @@ cpp::result<bool, std::string> MigrationManager::Migrate() {
   if (std::filesystem::exists(fmu::GetCortexDataPath() / kCortexDb)) {
     auto src_db_path = (fmu::GetCortexDataPath() / kCortexDb);
     auto backup_db_path = (fmu::GetCortexDataPath() / kCortexDbBackup);
-    if (auto res = mgr_helper_.BackupDatabase(src_db_path, backup_db_path.string());
+#if defined(_WIN32)
+    if (auto res = mgr_helper_.BackupDatabase(
+            src_db_path, cortex::wc::WstringToUtf8(backup_db_path.wstring()));
+#else
+    if (auto res =
+            mgr_helper_.BackupDatabase(src_db_path, backup_db_path.string());
+#endif
         res.has_error()) {
       CTL_INF("Error: backup database failed!");
       return res;