diff --git a/src/fu-device.c b/src/fu-device.c
index 2c7dff375..8140175c1 100644
--- a/src/fu-device.c
+++ b/src/fu-device.c
@@ -249,6 +249,12 @@ fu_device_add_child (FuDevice *device, FuDevice *child)
 	}
 	g_ptr_array_add (priv->children, g_object_ref (child));
 
+	/* copy from main device if unset */
+	if (fu_device_get_vendor (child) == NULL)
+		fu_device_set_vendor (child, fu_device_get_vendor (device));
+	if (fu_device_get_vendor_id (child) == NULL)
+		fu_device_set_vendor_id (child, fu_device_get_vendor_id (device));
+
 	/* ensure the parent is also set on the child */
 	fu_device_set_parent (child, device);
 }
diff --git a/src/fu-self-test.c b/src/fu-self-test.c
index 4a2e45ff1..8756c8a97 100644
--- a/src/fu-self-test.c
+++ b/src/fu-self-test.c
@@ -183,6 +183,7 @@ fu_engine_device_parent_func (void)
 	/* parent */
 	fu_device_set_id (device2, "parent");
 	fu_device_add_guid (device2, "parent-GUID");
+	fu_device_set_vendor (device2, "oem");
 
 	/* add another child */
 	fu_device_set_id (device3, "child2");
@@ -196,6 +197,8 @@ fu_engine_device_parent_func (void)
 	/* verify both children were adopted */
 	g_assert (fu_device_get_parent (device3) == device2);
 	g_assert (fu_device_get_parent (device1) == device2);
+	g_assert_cmpstr (fu_device_get_vendor (device3), ==, "oem");
+	g_assert_cmpstr (fu_device_get_vendor (device1), ==, "oem");
 }
 
 static void