--- iodev/devices.cc	(revision 12882)
+++ iodev/devices.cc	(working copy)
@@ -180,6 +180,7 @@
     PLUG_load_plugin(pci, PLUGTYPE_CORE);
     PLUG_load_plugin(pci2isa, PLUGTYPE_CORE);
 #if BX_SUPPORT_PCIUSB
+    PLUG_load_plugin(usb_common, PLUGTYPE_CORE);
     if (chipset == BX_PCI_CHIPSET_I440FX) {
       // UHCI is a part of the PIIX3, so load / enable it
       if (!PLUG_device_present("usb_uhci")) {