diff --git a/hw/usb/bus.c b/hw/usb/bus.c
index df7411fea8..07083349f5 100644
--- a/hw/usb/bus.c
+++ b/hw/usb/bus.c
@@ -310,13 +310,13 @@ typedef struct LegacyUSBFactory
 {
     const char *name;
     const char *usbdevice_name;
-    USBDevice *(*usbdevice_init)(const char *params);
+    USBDevice *(*usbdevice_init)(void);
 } LegacyUSBFactory;
 
 static GSList *legacy_usb_factory;
 
 void usb_legacy_register(const char *typename, const char *usbdevice_name,
-                         USBDevice *(*usbdevice_init)(const char *params))
+                         USBDevice *(*usbdevice_init)(void))
 {
     if (usbdevice_name) {
         LegacyUSBFactory *f = g_malloc0(sizeof(*f));
@@ -658,27 +658,17 @@ void hmp_info_usb(Monitor *mon, const QDict *qdict)
 }
 
 /* handle legacy -usbdevice cmd line option */
-USBDevice *usbdevice_create(const char *cmdline)
+USBDevice *usbdevice_create(const char *driver)
 {
     USBBus *bus = usb_bus_find(-1 /* any */);
     LegacyUSBFactory *f = NULL;
     Error *err = NULL;
     GSList *i;
-    char driver[32];
-    const char *params;
-    int len;
     USBDevice *dev;
 
-    params = strchr(cmdline,':');
-    if (params) {
-        params++;
-        len = params - cmdline;
-        if (len > sizeof(driver))
-            len = sizeof(driver);
-        pstrcpy(driver, len, cmdline);
-    } else {
-        params = "";
-        pstrcpy(driver, sizeof(driver), cmdline);
+    if (strchr(driver, ':')) {
+        error_report("usbdevice parameters are not supported anymore");
+        return NULL;
     }
 
     for (i = legacy_usb_factory; i; i = i->next) {
@@ -702,15 +692,7 @@ USBDevice *usbdevice_create(const char *cmdline)
         return NULL;
     }
 
-    if (f->usbdevice_init) {
-        dev = f->usbdevice_init(params);
-    } else {
-        if (*params) {
-            error_report("usbdevice %s accepts no params", driver);
-            return NULL;
-        }
-        dev = usb_new(f->name);
-    }
+    dev = f->usbdevice_init ? f->usbdevice_init() : usb_new(f->name);
     if (!dev) {
         error_report("Failed to create USB device '%s'", f->name);
         return NULL;
diff --git a/hw/usb/dev-serial.c b/hw/usb/dev-serial.c
index b58c4eb908..63047d79cf 100644
--- a/hw/usb/dev-serial.c
+++ b/hw/usb/dev-serial.c
@@ -614,7 +614,7 @@ static void usb_serial_realize(USBDevice *dev, Error **errp)
     s->intr = usb_ep_get(dev, USB_TOKEN_IN, 1);
 }
 
-static USBDevice *usb_braille_init(const char *unused)
+static USBDevice *usb_braille_init(void)
 {
     USBDevice *dev;
     Chardev *cdrv;
diff --git a/include/hw/usb.h b/include/hw/usb.h
index 9f42394efa..436e07b304 100644
--- a/include/hw/usb.h
+++ b/include/hw/usb.h
@@ -499,7 +499,7 @@ void usb_bus_new(USBBus *bus, size_t bus_size,
 void usb_bus_release(USBBus *bus);
 USBBus *usb_bus_find(int busnr);
 void usb_legacy_register(const char *typename, const char *usbdevice_name,
-                         USBDevice *(*usbdevice_init)(const char *params));
+                         USBDevice *(*usbdevice_init)(void));
 USBDevice *usb_new(const char *name);
 bool usb_realize_and_unref(USBDevice *dev, USBBus *bus, Error **errp);
 USBDevice *usb_create_simple(USBBus *bus, const char *name);