diff --git a/libc/arch-x86_64/syscalls/sync.S b/libc/arch-x86_64/syscalls/sync.S
index 9911715..97aa427 100644
--- a/libc/arch-x86_64/syscalls/sync.S
+++ b/libc/arch-x86_64/syscalls/sync.S
@@ -2,6 +2,8 @@
 
 #include <private/bionic_asm.h>
 
+    .hidden __set_errno
+
 ENTRY(sync)
     movl    $__NR_sync, %eax
     syscall