diff --git a/libc/arch-arm64/syscalls/munlock.S b/libc/arch-arm64/syscalls/munlock.S
index b1ec016..45d6d17 100644
--- a/libc/arch-arm64/syscalls/munlock.S
+++ b/libc/arch-arm64/syscalls/munlock.S
@@ -2,6 +2,8 @@
 
 #include <private/bionic_asm.h>
 
+    .hidden __set_errno
+
 ENTRY(munlock)
     mov     x8, __NR_munlock
     svc     #0