diff --git a/arch/sim/src/sim/posix/sim_alsa.c b/arch/sim/src/sim/posix/sim_alsa.c
index fbb8808917..440ef37993 100644
--- a/arch/sim/src/sim/posix/sim_alsa.c
+++ b/arch/sim/src/sim/posix/sim_alsa.c
@@ -560,11 +560,17 @@ static int sim_audio_stop(struct audio_lowerhalf_s *dev)
   priv->dev.upper(priv->dev.priv, AUDIO_CALLBACK_COMPLETE, NULL, OK);
 #endif
 
-  apb_free(priv->aux);
-  priv->aux = NULL;
+  if (priv->aux)
+    {
+      apb_free(priv->aux);
+      priv->aux = NULL;
+    }
 
-  priv->ops->uninit(priv->codec);
-  priv->ops = NULL;
+  if (priv->ops)
+    {
+      priv->ops->uninit(priv->codec);
+      priv->ops = NULL;
+    }
 
   return 0;
 }