diff --git a/libc/arch-arm64/syscalls/sigaltstack.S b/libc/arch-arm64/syscalls/sigaltstack.S
index 6052caa..46794d4 100644
--- a/libc/arch-arm64/syscalls/sigaltstack.S
+++ b/libc/arch-arm64/syscalls/sigaltstack.S
@@ -4,14 +4,18 @@
 
 ENTRY(sigaltstack)
     stp     x29, x30, [sp, #-16]!
+    .cfi_def_cfa_offset 16
+    .cfi_rel_offset x29, 0
+    .cfi_rel_offset x30, 8
     mov     x29,  sp
-    str     x8,       [sp, #-16]!
 
     mov     x8, __NR_sigaltstack
     svc     #0
 
-    ldr     x8,       [sp], #16
     ldp     x29, x30, [sp], #16
+    .cfi_def_cfa_offset 0
+    .cfi_restore x29
+    .cfi_restore x30
 
     cmn     x0, #(MAX_ERRNO + 1)
     cneg    x0, x0, hi