diff --git a/sys/kern/subr_syscall.c b/sys/kern/subr_syscall.c
--- a/sys/kern/subr_syscall.c
+++ b/sys/kern/subr_syscall.c
@@ -80,7 +80,7 @@
 	se = sa->callp;
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_SYSCALL))
-		ktrsyscall(sa->code, se->sy_narg, sa->args);
+		ktrsyscall(sa->code, error != 0 ? 0 : se->sy_narg, sa->args);
 #endif
 	KTR_START4(KTR_SYSC, "syscall", syscallname(p, sa->code),
 	    (uintptr_t)td, "pid:%d", td->td_proc->p_pid, "arg0:%p", sa->args[0],