diff --git a/libc/arch-arm/syscalls/prctl.S b/libc/arch-arm/syscalls/prctl.S
index 615a2fa..c8f68d3 100644
--- a/libc/arch-arm/syscalls/prctl.S
+++ b/libc/arch-arm/syscalls/prctl.S
@@ -2,6 +2,8 @@
 
 #include <private/bionic_asm.h>
 
+    .hidden __set_errno
+
 ENTRY(prctl)
     mov     ip, sp
     stmfd   sp!, {r4, r5, r6, r7}