diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 0b19ab1dbf68..c3be1f6015b3 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -985,6 +985,8 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 		} else {
 			pl->pl_flags = 0;
 		}
+		pl->pl_sigmask = td2->td_sigmask;
+		pl->pl_siglist = td2->td_siglist;
 		_PRELE(p);
 		PROC_UNLOCK(p);
 		return (0);
diff --git a/sys/sys/ptrace.h b/sys/sys/ptrace.h
index 93b1a7d6d0fc..8fd52cb4451e 100644
--- a/sys/sys/ptrace.h
+++ b/sys/sys/ptrace.h
@@ -33,6 +33,8 @@
 #ifndef	_SYS_PTRACE_H_
 #define	_SYS_PTRACE_H_
 
+#include <sys/_sigset.h>
+
 #define	PT_TRACE_ME	0	/* child declares it's being traced */
 #define	PT_READ_I	1	/* read word in child's I space */
 #define	PT_READ_D	2	/* read word in child's D space */
@@ -92,6 +94,8 @@ struct ptrace_lwpinfo {
 	int	pl_flags;	/* LWP flags. */
 #define	PL_FLAG_SA	0x01	/* M:N thread */
 #define	PL_FLAG_BOUND	0x02	/* M:N bound thread */
+	sigset_t	pl_sigmask;	/* LWP signal mask */
+	sigset_t	pl_siglist;	/* LWP pending signal */
 };
 
 #ifdef _KERNEL