diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1278,8 +1278,11 @@
 	saved_mask = td->td_sigmask;
 	SIGSETNAND(td->td_sigmask, waitset);
 	if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 ||
-	    !kern_sig_discard_ign)
-		td->td_pflags2 |= TDP2_SIGWAIT;
+	    !kern_sig_discard_ign) {
+		thread_lock(td);
+		td->td_flags |= TDF_SIGWAIT;
+		thread_unlock(td);
+	}
 	for (;;) {
 		mtx_lock(&ps->ps_mtx);
 		sig = cursig(td);
@@ -1343,7 +1346,9 @@
 		if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0)
 			traced = true;
 	}
-	td->td_pflags2 &= ~TDP2_SIGWAIT;
+	thread_lock(td);
+	td->td_flags &= ~TDF_SIGWAIT;
+	thread_unlock(td);
 
 	new_block = saved_mask;
 	SIGSETNAND(new_block, td->td_sigmask);
@@ -2951,7 +2956,7 @@
 		 */
 		if (SIGISMEMBER(ps->ps_sigignore, sig) &&
 		    (p->p_flag & P_TRACED) == 0 &&
-		    (td->td_pflags2 & TDP2_SIGWAIT) == 0) {
+		    (td->td_flags & TDF_SIGWAIT) == 0) {
 			sigqueue_delete(&td->td_sigqueue, sig);
 			sigqueue_delete(&p->p_sigqueue, sig);
 			continue;
@@ -3064,7 +3069,7 @@
 				mtx_lock(&ps->ps_mtx);
 				goto next;
 			} else if ((prop & SIGPROP_IGNORE) != 0 &&
-			    (td->td_pflags2 & TDP2_SIGWAIT) == 0) {
+			    (td->td_flags & TDF_SIGWAIT) == 0) {
 				/*
 				 * Default action is to ignore; drop it if
 				 * not in kern_sigtimedwait().
@@ -3075,7 +3080,7 @@
 			/*NOTREACHED*/
 
 		case (intptr_t)SIG_IGN:
-			if ((td->td_pflags2 & TDP2_SIGWAIT) == 0)
+			if ((td->td_flags & TDF_SIGWAIT) == 0)
 				break;		/* == ignore */
 			else
 				return (sig);
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -446,7 +446,7 @@
 #define	TDF_TIMEOUT	0x00000010 /* Timing out during sleep. */
 #define	TDF_IDLETD	0x00000020 /* This is a per-CPU idle thread. */
 #define	TDF_CANSWAP	0x00000040 /* Thread can be swapped. */
-#define	TDF_UNUSED80	0x00000080 /* unused. */
+#define	TDF_SIGWAIT	0x00000080 /* Ignore ignored signals */
 #define	TDF_KTH_SUSP	0x00000100 /* kthread is suspended */
 #define	TDF_ALLPROCSUSP	0x00000200 /* suspended by SINGLE_ALLPROC */
 #define	TDF_BOUNDARY	0x00000400 /* Thread suspended at user boundary */
@@ -531,7 +531,6 @@
 #define	TDP2_SBPAGES	0x00000001 /* Owns sbusy on some pages */
 #define	TDP2_COMPAT32RB	0x00000002 /* compat32 ABI for robust lists */
 #define	TDP2_ACCT	0x00000004 /* Doing accounting */
-#define	TDP2_SIGWAIT	0x00000008 /* Ignore ignored signals */
 
 /*
  * Reasons that the current thread can not be run yet.