diff --git a/libc/arch-x86_64/syscalls/mprotect.S b/libc/arch-x86_64/syscalls/mprotect.S
index d849bb1..44888da 100644
--- a/libc/arch-x86_64/syscalls/mprotect.S
+++ b/libc/arch-x86_64/syscalls/mprotect.S
@@ -2,6 +2,8 @@
 
 #include <private/bionic_asm.h>
 
+    .hidden __set_errno
+
 ENTRY(mprotect)
     movl    $__NR_mprotect, %eax
     syscall