diff --git a/src/mm-generic-cdma.c b/src/mm-generic-cdma.c
index d81c1b1..aad19f5 100644
--- a/src/mm-generic-cdma.c
+++ b/src/mm-generic-cdma.c
@@ -236,6 +245,7 @@ enable (MMModem *modem,
 
     if (!do_enable) {
         mm_serial_port_close (priv->primary);
+        mm_port_set_connected (priv->data, FALSE);
         mm_callback_info_schedule (info);
         return;
     }
diff --git a/src/mm-generic-gsm.c b/src/mm-generic-gsm.c
index 3a0c499..a7914d1 100644
--- a/src/mm-generic-gsm.c
+++ b/src/mm-generic-gsm.c
@@ -424,6 +424,7 @@ enable (MMModem *modem,
             mm_serial_port_flash (priv->primary, 1000, disable_flash_done, info);
         else
             disable_flash_done (priv->primary, info);
+        mm_port_set_connected (priv->data, FALSE);
     } else {
         if (mm_serial_port_open (priv->primary, &info->error))
             mm_serial_port_flash (priv->primary, 100, enable_flash_done, info);