diff --git a/photon/libc/sys/magenta/machine/x86_64/crt0.s b/photon/libc/sys/magenta/machine/x86_64/crt0.s
index a292280..01f97e2 100644
--- a/photon/libc/sys/magenta/machine/x86_64/crt0.s
+++ b/photon/libc/sys/magenta/machine/x86_64/crt0.s
@@ -14,5 +14,5 @@ _start:
     movq %rax, %rdx
     movq $1, %rsi /* MX_EXIT_ALL_THREADS */
     movq $0, %rdi /* MX_NULL_HANDLE */
-    movq $24, %rax /* mx_process_kill() */
+    movq $1, %rax /* mx_process_kill() */
     syscall