diff --git a/mdbx.h++ b/mdbx.h++
index 650673c4..4958f857 100644
--- a/mdbx.h++
+++ b/mdbx.h++
@@ -356,6 +356,9 @@ class cursor_managed;
      __cpp_lib_memory_resource >= 201603L && _GLIBCXX_USE_CXX11_ABI)
 /// \brief Default polymorphic allocator for modern code.
 using polymorphic_allocator = ::std::pmr::string::allocator_type;
+using default_allocator = polymorphic_allocator;
+#else
+using default_allocator = legacy_allocator;
 #endif /* __cpp_lib_memory_resource >= 201603L */
 
 /// \brief Default singe-byte string.
diff --git a/test/extra/maindb_ordinal.c++ b/test/extra/maindb_ordinal.c++
index f61d779e..e9918fd3 100644
--- a/test/extra/maindb_ordinal.c++
+++ b/test/extra/maindb_ordinal.c++
@@ -13,7 +13,7 @@ int main(int argc, const char *argv[]) {
                         mdbx::env::operate_parameters());
 
   using buffer =
-      mdbx::buffer<mdbx::polymorphic_allocator, mdbx::default_capacity_policy>;
+      mdbx::buffer<mdbx::default_allocator, mdbx::default_capacity_policy>;
   auto txn = env.start_write();
   auto map = txn.create_map(nullptr, mdbx::key_mode::ordinal,
                             mdbx::value_mode::single);