diff --git a/external/db_drivers/liblmdb/mdb.c b/external/db_drivers/liblmdb/mdb.c
index 4c9e2238..5efd7409 100644
--- a/external/db_drivers/liblmdb/mdb.c
+++ b/external/db_drivers/liblmdb/mdb.c
@@ -2428,7 +2428,7 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
 			rc = MDB_MAP_FULL;
 			goto fail;
 	}
-#ifdef _WIN32
+#if defined(_WIN32) && !defined(MDB_VL32)
 	if (!(env->me_flags & MDB_RDONLY)) {
 		void *p;
 		p = (MDB_page *)(env->me_map + env->me_psize * pgno);