diff --git a/sched/sched/sched_waitid.c b/sched/sched/sched_waitid.c
index 81955e44d15..330f26afec6 100644
--- a/sched/sched/sched_waitid.c
+++ b/sched/sched/sched_waitid.c
@@ -400,7 +400,7 @@ int waitid(idtype_t idtype, id_t id, FAR siginfo_t *info, int options)
             {
               /* Make sure that the thread it is our child. */
 
-              if (ctcb->group->tg_ppid != rtcb->pid)
+              if (ctcb->group->tg_ppid != rtcb->group->tg_pid)
                 {
                   errcode = ECHILD;
                 }
@@ -437,7 +437,8 @@ int waitid(idtype_t idtype, id_t id, FAR siginfo_t *info, int options)
 
           ctcb = nxsched_get_tcb((pid_t)id);
 
-          if (!ctcb || !ctcb->group || ctcb->group->tg_ppid != rtcb->pid)
+          if (!ctcb || !ctcb->group ||
+              ctcb->group->tg_ppid != rtcb->group->tg_pid)
             {
               errcode = ECHILD;
             }
diff --git a/sched/sched/sched_waitpid.c b/sched/sched/sched_waitpid.c
index 49a70fe974d..25e326c36f1 100644
--- a/sched/sched/sched_waitpid.c
+++ b/sched/sched/sched_waitpid.c
@@ -373,7 +373,8 @@ pid_t nxsched_waitpid(pid_t pid, FAR int *stat_loc, int options)
        */
 
       ctcb = nxsched_get_tcb(pid);
-      if (!ctcb || !ctcb->group || ctcb->group->tg_ppid != rtcb->pid ||
+      if (!ctcb || !ctcb->group ||
+          ctcb->group->tg_ppid != rtcb->group->tg_pid ||
           (ctcb->flags & TCB_FLAG_EXIT_PROCESSING) != 0)
         {
           ret = -ECHILD;