diff --git a/sched/sched/sched_waitid.c b/sched/sched/sched_waitid.c
index 53922239af..543a2a7e4b 100644
--- a/sched/sched/sched_waitid.c
+++ b/sched/sched/sched_waitid.c
@@ -167,9 +167,11 @@ int nx_waitid(int idtype, id_t id, FAR siginfo_t *info, int options)
        */
 
       ctcb = nxsched_get_tcb((pid_t)id);
-      if (ctcb != NULL)
+      if (ctcb && ctcb->group)
         {
-          if (ctcb->group->tg_ppid != rtcb->group->tg_pid)
+          /* Make sure that the thread it is our child. */
+
+          if (ctcb->group->tg_ppid != rtcb->pid)
             {
               ret = -ECHILD;
               goto errout;
@@ -209,7 +211,7 @@ int nx_waitid(int idtype, id_t id, FAR siginfo_t *info, int options)
 
       ctcb = nxsched_get_tcb((pid_t)id);
 
-      if (ctcb == NULL || ctcb->group->tg_ppid != rtcb->group->tg_pid)
+      if (!ctcb || !ctcb->group || ctcb->group->tg_ppid != rtcb->pid)
         {
           ret = -ECHILD;
           goto errout;
diff --git a/sched/sched/sched_waitpid.c b/sched/sched/sched_waitpid.c
index 64c5af3728..d13b718964 100644
--- a/sched/sched/sched_waitpid.c
+++ b/sched/sched/sched_waitpid.c
@@ -81,7 +81,11 @@ pid_t nx_waitpid(pid_t pid, int *stat_loc, int options)
   /* Then the task group corresponding to this PID */
 
   group = ctcb->group;
-  DEBUGASSERT(group);
+  if (group == NULL)
+    {
+      ret = -ECHILD;
+      goto errout;
+    }
 
   /* Lock this group so that it cannot be deleted until the wait completes */
 
@@ -230,7 +234,7 @@ pid_t nx_waitpid(pid_t pid, int *stat_loc, int options)
        */
 
       ctcb = nxsched_get_tcb(pid);
-      if (ctcb != NULL)
+      if (ctcb && ctcb->group)
         {
           /* Make sure that the thread it is our child. */
 
@@ -273,8 +277,7 @@ pid_t nx_waitpid(pid_t pid, int *stat_loc, int options)
        */
 
       ctcb = nxsched_get_tcb(pid);
-
-      if (ctcb == NULL || ctcb->group->tg_ppid != rtcb->group->tg_pid)
+      if (!ctcb || !ctcb->group || ctcb->group->tg_ppid != rtcb->pid)
         {
           ret = -ECHILD;
           goto errout;