diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 519a77ba214c..b30e7423549b 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1944,6 +1944,7 @@ static void __exit acm_exit(void)
 	usb_deregister(&acm_driver);
 	tty_unregister_driver(acm_tty_driver);
 	put_tty_driver(acm_tty_driver);
+	idr_destroy(&acm_minors);
 }
 
 module_init(acm_init);