diff --git a/src/os.c b/src/os.c
index 93e022a..6985587 100644
--- a/src/os.c
+++ b/src/os.c
@@ -625,6 +625,7 @@ void  _mi_os_free(void* p, size_t size, mi_stats_t* stats) {
 
 void* _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool* large, mi_os_tld_t* tld)
 {
+  UNUSED(tld);
   if (size == 0) return NULL;
   size = _mi_os_good_alloc_size(size);
   alignment = _mi_align_up(alignment, _mi_os_page_size());