diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 10209ec6ff4..3883fe4b325 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -1112,6 +1112,7 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 #endif
 		pl = addr;
 		pl->pl_lwpid = td2->td_tid;
+		pl->pl_event = PL_EVENT_NONE;
 		pl->pl_flags = 0;
 		if (td2->td_dbgflags & TDB_XSIG) {
 			pl->pl_event = PL_EVENT_SIGNAL;