diff --git a/libc/arch-x86/syscalls/sigaltstack.S b/libc/arch-x86/syscalls/sigaltstack.S
new file mode 100644
index 0000000..d39419d
--- /dev/null
+++ b/libc/arch-x86/syscalls/sigaltstack.S
@@ -0,0 +1,26 @@
+/* autogenerated by gensyscalls.py */
+#include <sys/linux-syscalls.h>
+
+    .text
+    .type sigaltstack, @function
+    .globl sigaltstack
+    .align 4
+
+sigaltstack:
+    pushl   %ebx
+    pushl   %ecx
+    mov     12(%esp), %ebx
+    mov     16(%esp), %ecx
+    movl    $__NR_sigaltstack, %eax
+    int     $0x80
+    cmpl    $-129, %eax
+    jb      1f
+    negl    %eax
+    pushl   %eax
+    call    __set_errno
+    addl    $4, %esp
+    orl     $-1, %eax
+1:
+    popl    %ecx
+    popl    %ebx
+    ret