diff --git a/sched/environ/env_dup.c b/sched/environ/env_dup.c
index f1b351ef4c..6070cc462c 100644
--- a/sched/environ/env_dup.c
+++ b/sched/environ/env_dup.c
@@ -78,7 +78,7 @@ int env_dup(FAR struct task_group_s *group, FAR char * const *envcp)
 
   /* Is there an environment ? */
 
-  if (envcp || (envcp = ptcb->group->tg_envp))
+  if (envcp || (envcp = ptcb->group->tg_envp) != NULL)
     {
       /* Count the strings */