diff --git a/ChangeLog b/ChangeLog
index ebd925ddc4..63e08e2f91 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2008-05-22  Tambet Ingo  <tambet@gmail.com>
+
+	* src/nm-gsm-device.c (device_state_changed): Make sure we don't leave the
+	serial device open when we're not connecting or connected.
+
+	* src/nm-cdma-device.c (device_state_changed): Ditto.
+
 2008-05-20  Dan Williams  <dcbw@redhat.com>
 
 	* system-settings/plugins/ifcfg-fedora/reader.c
diff --git a/src/nm-cdma-device.c b/src/nm-cdma-device.c
index 984df79fd9..4be18163c6 100644
--- a/src/nm-cdma-device.c
+++ b/src/nm-cdma-device.c
@@ -385,6 +385,19 @@ device_state_changed (NMDeviceInterface *device, NMDeviceState state, gpointer u
 	 */
 	if (state == NM_DEVICE_STATE_UNAVAILABLE)
 		priv->state_to_disconnected_id = g_idle_add (unavailable_to_disconnected, self);
+
+	/* Make sure we don't leave the serial device open */
+	switch (state) {
+	case NM_DEVICE_STATE_NEED_AUTH:
+	case NM_DEVICE_STATE_UNMANAGED:
+	case NM_DEVICE_STATE_UNAVAILABLE:
+	case NM_DEVICE_STATE_FAILED:
+	case NM_DEVICE_STATE_DISCONNECTED:
+		nm_serial_device_close (NM_SERIAL_DEVICE (self));
+		break;
+	default:
+		break;
+	}
 }
 
 static GObject*
diff --git a/src/nm-gsm-device.c b/src/nm-gsm-device.c
index 282ebd1939..c57a75c11c 100644
--- a/src/nm-gsm-device.c
+++ b/src/nm-gsm-device.c
@@ -697,6 +697,19 @@ device_state_changed (NMDeviceInterface *device, NMDeviceState state, gpointer u
 	 */
 	if (state == NM_DEVICE_STATE_UNAVAILABLE)
 		priv->state_to_disconnected_id = g_idle_add (unavailable_to_disconnected, self);
+
+	/* Make sure we don't leave the serial device open */
+	switch (state) {
+	case NM_DEVICE_STATE_NEED_AUTH:
+	case NM_DEVICE_STATE_UNMANAGED:
+	case NM_DEVICE_STATE_UNAVAILABLE:
+	case NM_DEVICE_STATE_FAILED:
+	case NM_DEVICE_STATE_DISCONNECTED:
+		nm_serial_device_close (NM_SERIAL_DEVICE (self));
+		break;
+	default:
+		break;
+	}
 }
 
 static GObject*