diff --git a/libc/malloc_debug/exported64.map b/libc/malloc_debug/exported64.map
index 1a6b30f..ec9d840 100644
--- a/libc/malloc_debug/exported64.map
+++ b/libc/malloc_debug/exported64.map
@@ -13,6 +13,7 @@
     debug_malloc_disable;
     debug_malloc_enable;
     debug_malloc_usable_size;
+    debug_mallopt;
     debug_memalign;
     debug_posix_memalign;
     debug_realloc;