diff --git a/sys/alpha/alpha/trap.c b/sys/alpha/alpha/trap.c
index 17dcb1491ea..f4af4bab97c 100644
--- a/sys/alpha/alpha/trap.c
+++ b/sys/alpha/alpha/trap.c
@@ -301,8 +301,8 @@ trap(a0, a1, a2, entry, framep)
 		if (td->td_ucred != p->p_ucred)
 			cred_update_thread(td);
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
-			mtx_lock_spin(&sched_lock);
 			PROC_LOCK(p);
+			mtx_lock_spin(&sched_lock);
 			thread_exit();
 			/* NOTREACHED */
 		}
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 8282416b8ea..fddb5176b36 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -273,8 +273,8 @@ trap(frame)
 		 * But check if we are the single thread first!
 		 */
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
+			PROC_LOCK(p); /* check if thisis really needed */
 			mtx_lock_spin(&sched_lock);
-			PROC_LOCK(p);
 			thread_exit();
 			/* NOTREACHED */
 		}
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 8282416b8ea..fddb5176b36 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -273,8 +273,8 @@ trap(frame)
 		 * But check if we are the single thread first!
 		 */
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
+			PROC_LOCK(p); /* check if thisis really needed */
 			mtx_lock_spin(&sched_lock);
-			PROC_LOCK(p);
 			thread_exit();
 			/* NOTREACHED */
 		}
diff --git a/sys/ia64/ia64/trap.c b/sys/ia64/ia64/trap.c
index 09d824f9a81..74dfebff7a4 100644
--- a/sys/ia64/ia64/trap.c
+++ b/sys/ia64/ia64/trap.c
@@ -337,7 +337,7 @@ trap(int vector, int imm, struct trapframe *framep)
 			cred_update_thread(td);
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
 			mtx_lock_spin(&sched_lock);
-			thread_exit();
+			thread_exit(); /* XXXKSE need proc lock? */
 			/* NOTREACHED */
 		}
 	} else {
diff --git a/sys/sparc64/sparc64/trap.c b/sys/sparc64/sparc64/trap.c
index f39d2f6a4c5..2fe9bb38fee 100644
--- a/sys/sparc64/sparc64/trap.c
+++ b/sys/sparc64/sparc64/trap.c
@@ -193,7 +193,7 @@ trap(struct trapframe *tf)
 			cred_update_thread(td);
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
 			mtx_lock_spin(&sched_lock);
-			thread_exit();
+			thread_exit(); /* XXXKSE need proc lock? */
 			/* NOTREACHED */
 		}
  	} else {