diff --git a/drivers/firmware/turris-mox-rwtm.c b/drivers/firmware/turris-mox-rwtm.c
index c2d34dc8ba46..fa4b904d74df 100644
--- a/drivers/firmware/turris-mox-rwtm.c
+++ b/drivers/firmware/turris-mox-rwtm.c
@@ -2,7 +2,7 @@
 /*
  * Turris Mox rWTM firmware driver
  *
- * Copyright (C) 2019 Marek Behún <kabel@kernel.org>
+ * Copyright (C) 2019, 2024 Marek Behún <kabel@kernel.org>
  */
 
 #include <linux/armada-37xx-rwtm-mailbox.h>
@@ -174,6 +174,9 @@ static void mox_rwtm_rx_callback(struct mbox_client *cl, void *data)
 	struct mox_rwtm *rwtm = dev_get_drvdata(cl->dev);
 	struct armada_37xx_rwtm_rx_msg *msg = data;
 
+	if (completion_done(&rwtm->cmd_done))
+		return;
+
 	rwtm->reply = *msg;
 	complete(&rwtm->cmd_done);
 }