diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 52a0c405713..2685a8b1384 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -2436,9 +2436,10 @@ ptracestop(struct thread *td, int sig)
 		}
 stopme:
 		thread_suspend_switch(td);
-		if (!(p->p_flag & P_TRACED)) {
+		if (p->p_xthread == td)
+			p->p_xthread = NULL;
+		if (!(p->p_flag & P_TRACED))
 			break;
-		}
 		if (td->td_dbgflags & TDB_SUSPEND) {
 			if (p->p_flag & P_SINGLE_EXIT)
 				break;