diff --git a/libc/arch-x86/syscalls/__setuid.S b/libc/arch-x86/syscalls/__setuid.S
new file mode 100644
index 0000000..1e5f285
--- /dev/null
+++ b/libc/arch-x86/syscalls/__setuid.S
@@ -0,0 +1,23 @@
+/* autogenerated by gensyscalls.py */
+#include <sys/linux-syscalls.h>
+
+    .text
+    .type __setuid, @function
+    .globl __setuid
+    .align 4
+
+__setuid:
+    pushl   %ebx
+    mov     8(%esp), %ebx
+    movl    $__NR_setuid32, %eax
+    int     $0x80
+    cmpl    $-129, %eax
+    jb      1f
+    negl    %eax
+    pushl   %eax
+    call    __set_errno
+    addl    $4, %esp
+    orl     $-1, %eax
+1:
+    popl    %ebx
+    ret