diff --git a/libusb/os/windows_nt_common.c b/libusb/os/windows_nt_common.c
index ad17678..92dbde5 100644
--- a/libusb/os/windows_nt_common.c
+++ b/libusb/os/windows_nt_common.c
@@ -729,9 +729,10 @@ static int windows_set_option(struct libusb_context *ctx, enum libusb_option opt
 			return LIBUSB_ERROR_NOT_FOUND;
 		}
 		return LIBUSB_SUCCESS;
+	default:
+		return LIBUSB_ERROR_NOT_SUPPORTED;
 	}
 
-	return LIBUSB_ERROR_NOT_SUPPORTED;
 }
 
 static int windows_get_device_list(struct libusb_context *ctx, struct discovered_devs **discdevs)
diff --git a/libusb/os/windows_usbdk.c b/libusb/os/windows_usbdk.c
index 089e2a5..6b16675 100644
--- a/libusb/os/windows_usbdk.c
+++ b/libusb/os/windows_usbdk.c
@@ -496,13 +496,11 @@ static int usbdk_do_control_transfer(struct usbi_transfer *itransfer)
 	struct usbdk_transfer_priv *transfer_priv = _usbdk_transfer_priv(itransfer);
 	struct libusb_context *ctx = TRANSFER_CTX(transfer);
 	OVERLAPPED *overlapped = transfer_priv->pollable_fd.overlapped;
-	ULONG Length;
 	TransferResult transResult;
 
 	transfer_priv->request.Buffer = (PVOID64)transfer->buffer;
 	transfer_priv->request.BufferLength = transfer->length;
 	transfer_priv->request.TransferType = ControlTransferType;
-	Length = (ULONG)transfer->length;
 
 	if (transfer->buffer[0] & LIBUSB_ENDPOINT_IN)
 		transResult = usbdk_helper.ReadPipe(priv->redirector_handle, &transfer_priv->request, overlapped);
diff --git a/libusb/os/windows_usbdk.h b/libusb/os/windows_usbdk.h
index 0de2675..77660ae 100644
--- a/libusb/os/windows_usbdk.h
+++ b/libusb/os/windows_usbdk.h
@@ -25,12 +25,6 @@
 
 #include "windows_nt_common.h"
 
-static inline void UsbDkFillIDStruct(USB_DK_DEVICE_ID *ID, const WCHAR *DeviceID, const WCHAR *InstanceID)
-{
-	wcsncpy(ID->DeviceID, DeviceID, MAX_DEVICE_ID_LEN);
-	wcsncpy(ID->InstanceID, InstanceID, MAX_DEVICE_ID_LEN);
-}
-
 typedef struct USB_DK_CONFIG_DESCRIPTOR_REQUEST {
 	USB_DK_DEVICE_ID ID;
 	ULONG64 Index;
diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index ea7dafb..796ce88 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11284
+#define LIBUSB_NANO 11285