diff --git a/kernel/syscall/processctl.c b/kernel/syscall/processctl.c
index 3073c53..af67751 100644
--- a/kernel/syscall/processctl.c
+++ b/kernel/syscall/processctl.c
@@ -6,14 +6,12 @@
 #include "util/util.h"
 #include "sysdefs/processctl.h"
 
-#define PID_SELF_MAGIC 0x5E1F
-
 int32_t SYSCALL3(sys_processctl, pid1, cmd1, optsptr1) {
   uint64_t pid = pid1;
   uint64_t cmd = cmd1;
   int32_t ret = E_OK;
   
-  if (pid == PID_SELF_MAGIC) {
+  if (pid == -1) {
     pid = PROCS.current->pid;
   }
 
diff --git a/ulib/_start.S b/ulib/_start.S
index fcea48a..60d86c3 100644
--- a/ulib/_start.S
+++ b/ulib/_start.S
@@ -7,6 +7,6 @@ _start:
   call _premain
 
   movq $2, %rax      // sys processctl
-  movq $0x5E1F, %rdi // self magic num
+  movq $-1, %rdi // self magic num
   movq $0, %rsi       // kill cmd
   int $0x80