diff --git a/drivers/thermal/thermal_procfs.c b/drivers/thermal/thermal_procfs.c
index b3dbcbb7f1..efef0ea162 100644
--- a/drivers/thermal/thermal_procfs.c
+++ b/drivers/thermal/thermal_procfs.c
@@ -316,9 +316,8 @@ int thermal_zone_procfs_register(FAR struct thermal_zone_device_s *zdev)
   FAR struct thermal_procfs_s *p;
 
   p = kmm_zalloc(sizeof(struct thermal_procfs_s));
-  if (!p)
+  if (p == NULL)
     {
-      nxmutex_unlock(&g_thermal_procfs_lock);
       return -ENOMEM;
     }