diff --git a/libc/arch-arm64/syscalls/flock.S b/libc/arch-arm64/syscalls/flock.S
index 0e1c3f5..2151d6c 100644
--- a/libc/arch-arm64/syscalls/flock.S
+++ b/libc/arch-arm64/syscalls/flock.S
@@ -2,6 +2,8 @@
 
 #include <private/bionic_asm.h>
 
+    .hidden __set_errno
+
 ENTRY(flock)
     mov     x8, __NR_flock
     svc     #0