diff --git a/drivers/wireless/ieee802154/xbee/xbee_mac.c b/drivers/wireless/ieee802154/xbee/xbee_mac.c
index c4c52442d0..3fd8032573 100644
--- a/drivers/wireless/ieee802154/xbee/xbee_mac.c
+++ b/drivers/wireless/ieee802154/xbee/xbee_mac.c
@@ -320,6 +320,7 @@ int xbee_req_data(XBEEHANDLE xbee,
     }
   else
     {
+      nxmutex_unlock(&priv->tx_lock);
       return -EINVAL;
     }