diff --git a/libusb/os/windows_common.c b/libusb/os/windows_common.c
index 119ed49aae114b720ec73e11a7bc13578a11d3a9..d484f8fd8728e96fea9be352f0b3e56bacf2c2f7 100644
--- a/libusb/os/windows_common.c
+++ b/libusb/os/windows_common.c
@@ -294,15 +294,18 @@ enum libusb_transfer_status usbd_status_to_libusb_transfer_status(USBD_STATUS st
  */
 void windows_force_sync_completion(struct usbi_transfer *itransfer, ULONG size)
 {
+	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_context_priv *priv = usbi_get_context_priv(TRANSFER_CTX(transfer));
 	struct windows_transfer_priv *transfer_priv = usbi_get_transfer_priv(itransfer);
 	OVERLAPPED *overlapped = &transfer_priv->overlapped;
 
-	usbi_dbg("transfer %p, length %lu", USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer), ULONG_CAST(size));
+	usbi_dbg("transfer %p, length %lu", transfer, ULONG_CAST(size));
 
 	overlapped->Internal = (ULONG_PTR)STATUS_SUCCESS;
 	overlapped->InternalHigh = (ULONG_PTR)size;
 
-	usbi_signal_transfer_completion(itransfer);
+	if (!PostQueuedCompletionStatus(priv->completion_port, (DWORD)size, (ULONG_PTR)transfer->dev_handle, overlapped))
+		usbi_err(TRANSFER_CTX(transfer), "failed to post I/O completion: %s", windows_error_str(0));
 }
 
 /* Windows version detection */
@@ -416,8 +419,11 @@ static unsigned __stdcall windows_iocp_thread(void *arg)
 	DWORD num_bytes;
 	ULONG_PTR completion_key;
 	OVERLAPPED *overlapped;
+	struct libusb_device_handle *dev_handle;
+	struct windows_device_handle_priv *handle_priv;
 	struct windows_transfer_priv *transfer_priv;
 	struct usbi_transfer *itransfer;
+	bool found;
 
 	usbi_dbg("I/O completion thread started");
 
@@ -435,7 +441,29 @@ static unsigned __stdcall windows_iocp_thread(void *arg)
 			break;
 		}
 
-		transfer_priv = container_of(overlapped, struct windows_transfer_priv, overlapped);
+		// Find the transfer associated with the OVERLAPPED that just completed.
+		// If we cannot find a match, the I/O operation originated from outside of libusb
+		// (e.g. within libusbK) and we need to ignore it.
+		dev_handle = (struct libusb_device_handle *)completion_key;
+		handle_priv = usbi_get_device_handle_priv(dev_handle);
+		found = false;
+		usbi_mutex_lock(&dev_handle->lock);
+		list_for_each_entry(transfer_priv, &handle_priv->active_transfers, list, struct windows_transfer_priv) {
+			if (overlapped == &transfer_priv->overlapped) {
+				// This OVERLAPPED belongs to us, remove the transfer from the device handle's list
+				list_del(&transfer_priv->list);
+				found = true;
+				break;
+			}
+		}
+		usbi_mutex_unlock(&dev_handle->lock);
+
+		if (!found) {
+			usbi_dbg("ignoring overlapped %p for handle %p (device %u.%u)",
+				overlapped, dev_handle, dev_handle->dev->bus_number, dev_handle->dev->device_address);
+			continue;
+		}
+
 		itransfer = (struct usbi_transfer *)((unsigned char *)transfer_priv + PTR_ALIGN(sizeof(*transfer_priv)));
 		usbi_dbg("transfer %p completed, length %lu",
 			 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer), ULONG_CAST(num_bytes));
@@ -614,6 +642,9 @@ static int windows_get_device_list(struct libusb_context *ctx, struct discovered
 static int windows_open(struct libusb_device_handle *dev_handle)
 {
 	struct windows_context_priv *priv = usbi_get_context_priv(HANDLE_CTX(dev_handle));
+	struct windows_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+
+	list_init(&handle_priv->active_transfers);
 	return priv->backend->open(dev_handle);
 }
 
@@ -698,8 +729,10 @@ static void windows_destroy_device(struct libusb_device *dev)
 static int windows_submit_transfer(struct usbi_transfer *itransfer)
 {
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
-	struct libusb_context *ctx = TRANSFER_CTX(transfer);
+	struct libusb_device_handle *dev_handle = transfer->dev_handle;
+	struct libusb_context *ctx = HANDLE_CTX(dev_handle);
 	struct windows_context_priv *priv = usbi_get_context_priv(ctx);
+	struct windows_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
 	struct windows_transfer_priv *transfer_priv = usbi_get_transfer_priv(itransfer);
 	int r;
 
@@ -722,8 +755,18 @@ static int windows_submit_transfer(struct usbi_transfer *itransfer)
 		transfer_priv->handle = NULL;
 	}
 
+	// Add transfer to the device handle's list
+	usbi_mutex_lock(&dev_handle->lock);
+	list_add_tail(&transfer_priv->list, &handle_priv->active_transfers);
+	usbi_mutex_unlock(&dev_handle->lock);
+
 	r = priv->backend->submit_transfer(itransfer);
 	if (r != LIBUSB_SUCCESS) {
+		// Remove the unsuccessful transfer from the device handle's list
+		usbi_mutex_lock(&dev_handle->lock);
+		list_del(&transfer_priv->list);
+		usbi_mutex_unlock(&dev_handle->lock);
+
 		// Always call the backend's clear_transfer_priv() function on failure
 		priv->backend->clear_transfer_priv(itransfer);
 		transfer_priv->handle = NULL;
@@ -881,6 +924,6 @@ const struct usbi_os_backend usbi_backend = {
 	windows_handle_transfer_completion,
 	sizeof(struct windows_context_priv),
 	sizeof(union windows_device_priv),
-	sizeof(union windows_device_handle_priv),
+	sizeof(struct windows_device_handle_priv),
 	sizeof(struct windows_transfer_priv),
 };
diff --git a/libusb/os/windows_common.h b/libusb/os/windows_common.h
index 0c4b94c8444b0ee5e346303ecaf8b03c216e8108..cbeff60476fdb25b800c29307bf2e75bf1b80aeb 100644
--- a/libusb/os/windows_common.h
+++ b/libusb/os/windows_common.h
@@ -336,20 +336,36 @@ union windows_device_priv {
 	struct winusb_device_priv winusb_priv;
 };
 
-union windows_device_handle_priv {
-	struct usbdk_device_handle_priv usbdk_priv;
-	struct winusb_device_handle_priv winusb_priv;
+struct windows_device_handle_priv {
+	struct list_head active_transfers;
+	union {
+		struct usbdk_device_handle_priv usbdk_priv;
+		struct winusb_device_handle_priv winusb_priv;
+	};
 };
 
 struct windows_transfer_priv {
 	OVERLAPPED overlapped;
 	HANDLE handle;
+	struct list_head list;
 	union {
 		struct usbdk_transfer_priv usbdk_priv;
 		struct winusb_transfer_priv winusb_priv;
 	};
 };
 
+static inline struct usbdk_device_handle_priv *get_usbdk_device_handle_priv(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	return &handle_priv->usbdk_priv;
+}
+
+static inline struct winusb_device_handle_priv *get_winusb_device_handle_priv(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	return &handle_priv->winusb_priv;
+}
+
 static inline OVERLAPPED *get_transfer_priv_overlapped(struct usbi_transfer *itransfer)
 {
 	struct windows_transfer_priv *transfer_priv = usbi_get_transfer_priv(itransfer);
diff --git a/libusb/os/windows_usbdk.c b/libusb/os/windows_usbdk.c
index c9ebfcf79ba498f8f628d45042052214b2caa968..30c6c7d26b96b127fa68bc41a61171a52264ad1c 100644
--- a/libusb/os/windows_usbdk.c
+++ b/libusb/os/windows_usbdk.c
@@ -414,7 +414,7 @@ static int usbdk_open(struct libusb_device_handle *dev_handle)
 
 	device_priv->system_handle = usbdk_helper.GetRedirectorSystemHandle(device_priv->redirector_handle);
 
-	if (CreateIoCompletionPort(device_priv->system_handle, priv->completion_port, 0, 0) == NULL) {
+	if (CreateIoCompletionPort(device_priv->system_handle, priv->completion_port, (ULONG_PTR)dev_handle, 0) == NULL) {
 		usbi_err(ctx, "failed to associate handle to I/O completion port: %s", windows_error_str(0));
 		usbdk_helper.StopRedirect(device_priv->redirector_handle);
 		device_priv->system_handle = NULL;
diff --git a/libusb/os/windows_winusb.c b/libusb/os/windows_winusb.c
index f291b8e543b2db9b216ea7376319b9abfd24ca4f..3a2eb57e4922289d2ce82d5bfa835dc7d9443199 100644
--- a/libusb/os/windows_winusb.c
+++ b/libusb/os/windows_winusb.c
@@ -465,9 +465,9 @@ static int get_interface_by_endpoint(struct libusb_config_descriptor *conf_desc,
 /*
  * Open a device and associate the HANDLE with the context's I/O completion port
  */
-static HANDLE windows_open(struct libusb_device *dev, const char *path, DWORD access)
+static HANDLE windows_open(struct libusb_device_handle *dev_handle, const char *path, DWORD access)
 {
-	struct libusb_context *ctx = DEVICE_CTX(dev);
+	struct libusb_context *ctx = HANDLE_CTX(dev_handle);
 	struct windows_context_priv *priv = usbi_get_context_priv(ctx);
 	HANDLE handle;
 
@@ -475,7 +475,7 @@ static HANDLE windows_open(struct libusb_device *dev, const char *path, DWORD ac
 	if (handle == INVALID_HANDLE_VALUE)
 		return handle;
 
-	if (CreateIoCompletionPort(handle, priv->completion_port, 0, 0) == NULL) {
+	if (CreateIoCompletionPort(handle, priv->completion_port, (ULONG_PTR)dev_handle, 0) == NULL) {
 		usbi_err(ctx, "failed to associate handle to I/O completion port: %s", windows_error_str(0));
 		CloseHandle(handle);
 		return INVALID_HANDLE_VALUE;
@@ -570,7 +570,7 @@ static int get_sub_api(char *driver, int api)
 static int auto_claim(struct libusb_transfer *transfer, int *interface_number, int api_type)
 {
 	struct winusb_device_handle_priv *handle_priv =
-		usbi_get_device_handle_priv(transfer->dev_handle);
+		get_winusb_device_handle_priv(transfer->dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	int current_interface = *interface_number;
 	int r = LIBUSB_SUCCESS;
@@ -617,7 +617,7 @@ static void auto_release(struct usbi_transfer *itransfer)
 	struct winusb_transfer_priv *transfer_priv = get_winusb_transfer_priv(itransfer);
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 	libusb_device_handle *dev_handle = transfer->dev_handle;
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	int r;
 
 	usbi_mutex_lock(&autoclaim_lock);
@@ -2352,7 +2352,7 @@ static void winusbx_exit(void)
 static int winusbx_open(int sub_api, struct libusb_device_handle *dev_handle)
 {
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	HANDLE file_handle;
 	int i;
 
@@ -2362,7 +2362,7 @@ static int winusbx_open(int sub_api, struct libusb_device_handle *dev_handle)
 	for (i = 0; i < USB_MAXINTERFACES; i++) {
 		if ((priv->usb_interface[i].path != NULL)
 				&& (priv->usb_interface[i].apib->id == USB_API_WINUSBX)) {
-			file_handle = windows_open(dev_handle->dev, priv->usb_interface[i].path, GENERIC_READ | GENERIC_WRITE);
+			file_handle = windows_open(dev_handle, priv->usb_interface[i].path, GENERIC_READ | GENERIC_WRITE);
 			if (file_handle == INVALID_HANDLE_VALUE) {
 				usbi_err(HANDLE_CTX(dev_handle), "could not open device %s (interface %d): %s", priv->usb_interface[i].path, i, windows_error_str(0));
 				switch (GetLastError()) {
@@ -2384,7 +2384,7 @@ static int winusbx_open(int sub_api, struct libusb_device_handle *dev_handle)
 
 static void winusbx_close(int sub_api, struct libusb_device_handle *dev_handle)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	HANDLE handle;
 	int i;
@@ -2429,7 +2429,7 @@ static void winusbx_close(int sub_api, struct libusb_device_handle *dev_handle)
 
 static int winusbx_configure_endpoints(int sub_api, struct libusb_device_handle *dev_handle, uint8_t iface)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	HANDLE winusb_handle = handle_priv->interface_handle[iface].api_handle;
 	UCHAR policy;
@@ -2483,7 +2483,7 @@ static int winusbx_configure_endpoints(int sub_api, struct libusb_device_handle
 static int winusbx_claim_interface(int sub_api, struct libusb_device_handle *dev_handle, uint8_t iface)
 {
 	struct libusb_context *ctx = HANDLE_CTX(dev_handle);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	bool is_using_usbccgp = (priv->apib->id == USB_API_COMPOSITE);
 	HDEVINFO dev_info;
@@ -2534,7 +2534,7 @@ static int winusbx_claim_interface(int sub_api, struct libusb_device_handle *dev
 					*dev_interface_path_guid_start = '\0';
 
 					if (strncmp(dev_interface_path, priv->usb_interface[iface].path, strlen(dev_interface_path)) == 0) {
-						file_handle = windows_open(dev_handle->dev, filter_path, GENERIC_READ | GENERIC_WRITE);
+						file_handle = windows_open(dev_handle, filter_path, GENERIC_READ | GENERIC_WRITE);
 						if (file_handle != INVALID_HANDLE_VALUE) {
 							if (WinUSBX[sub_api].Initialize(file_handle, &winusb_handle)) {
 								// Replace the existing file handle with the working one
@@ -2599,7 +2599,7 @@ static int winusbx_claim_interface(int sub_api, struct libusb_device_handle *dev
 
 static int winusbx_release_interface(int sub_api, struct libusb_device_handle *dev_handle, uint8_t iface)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	HANDLE winusb_handle;
 
@@ -2620,7 +2620,7 @@ static int winusbx_release_interface(int sub_api, struct libusb_device_handle *d
  */
 static int get_valid_interface(struct libusb_device_handle *dev_handle, int api_id)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	int i;
 
@@ -2644,7 +2644,7 @@ static int get_valid_interface(struct libusb_device_handle *dev_handle, int api_
 */
 static int check_valid_interface(struct libusb_device_handle *dev_handle, unsigned short interface, int api_id)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 
 	if (interface >= USB_MAXINTERFACES)
@@ -2691,7 +2691,7 @@ static int winusbx_submit_control_transfer(int sub_api, struct usbi_transfer *it
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	struct winusb_transfer_priv *transfer_priv = get_winusb_transfer_priv(itransfer);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(transfer->dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(transfer->dev_handle);
 	PWINUSB_SETUP_PACKET setup = (PWINUSB_SETUP_PACKET)transfer->buffer;
 	ULONG size;
 	HANDLE winusb_handle;
@@ -2747,7 +2747,7 @@ static int winusbx_submit_control_transfer(int sub_api, struct usbi_transfer *it
 
 static int winusbx_set_interface_altsetting(int sub_api, struct libusb_device_handle *dev_handle, uint8_t iface, uint8_t altsetting)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	HANDLE winusb_handle;
 
@@ -2803,7 +2803,7 @@ static int winusbx_submit_iso_transfer(int sub_api, struct usbi_transfer *itrans
 {
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 	struct winusb_transfer_priv *transfer_priv = get_winusb_transfer_priv(itransfer);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(transfer->dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(transfer->dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	HANDLE winusb_handle;
 	OVERLAPPED *overlapped;
@@ -2993,7 +2993,7 @@ static int winusbx_submit_bulk_transfer(int sub_api, struct usbi_transfer *itran
 {
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 	struct winusb_transfer_priv *transfer_priv = get_winusb_transfer_priv(itransfer);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(transfer->dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(transfer->dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	HANDLE winusb_handle;
 	OVERLAPPED *overlapped;
@@ -3034,7 +3034,7 @@ static int winusbx_submit_bulk_transfer(int sub_api, struct usbi_transfer *itran
 
 static int winusbx_clear_halt(int sub_api, struct libusb_device_handle *dev_handle, unsigned char endpoint)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	HANDLE winusb_handle;
 	int current_interface;
@@ -3061,7 +3061,7 @@ static int winusbx_clear_halt(int sub_api, struct libusb_device_handle *dev_hand
 static int winusbx_cancel_transfer(int sub_api, struct usbi_transfer *itransfer)
 {
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(transfer->dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(transfer->dev_handle);
 	struct winusb_transfer_priv *transfer_priv = get_winusb_transfer_priv(itransfer);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	int current_interface = transfer_priv->interface_number;
@@ -3091,7 +3091,7 @@ static int winusbx_cancel_transfer(int sub_api, struct usbi_transfer *itransfer)
 // TODO: (post hotplug): see if we can force eject the device and redetect it (reuse hotplug?)
 static int winusbx_reset_device(int sub_api, struct libusb_device_handle *dev_handle)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	HANDLE winusb_handle;
 	int i, j;
@@ -3644,7 +3644,7 @@ static int hid_open(int sub_api, struct libusb_device_handle *dev_handle)
 {
 	struct libusb_device *dev = dev_handle->dev;
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	HIDD_ATTRIBUTES hid_attributes;
 	PHIDP_PREPARSED_DATA preparsed_data = NULL;
 	HIDP_CAPS capabilities;
@@ -3669,7 +3669,7 @@ static int hid_open(int sub_api, struct libusb_device_handle *dev_handle)
 	for (i = 0; i < USB_MAXINTERFACES; i++) {
 		if ((priv->usb_interface[i].path != NULL)
 				&& (priv->usb_interface[i].apib->id == USB_API_HID)) {
-			hid_handle = windows_open(dev, priv->usb_interface[i].path, GENERIC_READ | GENERIC_WRITE);
+			hid_handle = windows_open(dev_handle, priv->usb_interface[i].path, GENERIC_READ | GENERIC_WRITE);
 			/*
 			 * http://www.lvr.com/hidfaq.htm: Why do I receive "Access denied" when attempting to access my HID?
 			 * "Windows 2000 and later have exclusive read/write access to HIDs that are configured as a system
@@ -3679,7 +3679,7 @@ static int hid_open(int sub_api, struct libusb_device_handle *dev_handle)
 			 */
 			if (hid_handle == INVALID_HANDLE_VALUE) {
 				usbi_warn(HANDLE_CTX(dev_handle), "could not open HID device in R/W mode (keyboard or mouse?) - trying without");
-				hid_handle = windows_open(dev, priv->usb_interface[i].path, 0);
+				hid_handle = windows_open(dev_handle, priv->usb_interface[i].path, 0);
 				if (hid_handle == INVALID_HANDLE_VALUE) {
 					usbi_err(HANDLE_CTX(dev_handle), "could not open device %s (interface %d): %s", priv->path, i, windows_error_str(0));
 					switch (GetLastError()) {
@@ -3793,7 +3793,7 @@ static int hid_open(int sub_api, struct libusb_device_handle *dev_handle)
 static void hid_close(int sub_api, struct libusb_device_handle *dev_handle)
 {
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	HANDLE file_handle;
 	int i;
 
@@ -3813,7 +3813,7 @@ static void hid_close(int sub_api, struct libusb_device_handle *dev_handle)
 
 static int hid_claim_interface(int sub_api, struct libusb_device_handle *dev_handle, uint8_t iface)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 
 	UNUSED(sub_api);
@@ -3837,7 +3837,7 @@ static int hid_claim_interface(int sub_api, struct libusb_device_handle *dev_han
 
 static int hid_release_interface(int sub_api, struct libusb_device_handle *dev_handle, uint8_t iface)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 
 	UNUSED(sub_api);
@@ -3874,7 +3874,7 @@ static int hid_submit_control_transfer(int sub_api, struct usbi_transfer *itrans
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 	struct winusb_transfer_priv *transfer_priv = get_winusb_transfer_priv(itransfer);
 	struct libusb_device_handle *dev_handle = transfer->dev_handle;
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	WINUSB_SETUP_PACKET *setup = (WINUSB_SETUP_PACKET *)transfer->buffer;
 	HANDLE hid_handle;
@@ -3972,7 +3972,7 @@ static int hid_submit_bulk_transfer(int sub_api, struct usbi_transfer *itransfer
 {
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 	struct winusb_transfer_priv *transfer_priv = get_winusb_transfer_priv(itransfer);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(transfer->dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(transfer->dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	HANDLE hid_handle;
 	OVERLAPPED *overlapped;
@@ -4041,7 +4041,7 @@ static int hid_submit_bulk_transfer(int sub_api, struct usbi_transfer *itransfer
 
 static int hid_reset_device(int sub_api, struct libusb_device_handle *dev_handle)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	HANDLE hid_handle;
 	int current_interface;
 
@@ -4060,7 +4060,7 @@ static int hid_reset_device(int sub_api, struct libusb_device_handle *dev_handle
 
 static int hid_clear_halt(int sub_api, struct libusb_device_handle *dev_handle, unsigned char endpoint)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	HANDLE hid_handle;
 	int current_interface;
@@ -4316,7 +4316,7 @@ static int composite_submit_control_transfer(int sub_api, struct usbi_transfer *
 static int composite_submit_bulk_transfer(int sub_api, struct usbi_transfer *itransfer)
 {
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(transfer->dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(transfer->dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	int current_interface;
 
@@ -4337,7 +4337,7 @@ static int composite_submit_bulk_transfer(int sub_api, struct usbi_transfer *itr
 static int composite_submit_iso_transfer(int sub_api, struct usbi_transfer *itransfer)
 {
 	struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(transfer->dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(transfer->dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(transfer->dev_handle->dev);
 	int current_interface;
 
@@ -4357,7 +4357,7 @@ static int composite_submit_iso_transfer(int sub_api, struct usbi_transfer *itra
 
 static int composite_clear_halt(int sub_api, struct libusb_device_handle *dev_handle, unsigned char endpoint)
 {
-	struct winusb_device_handle_priv *handle_priv = usbi_get_device_handle_priv(dev_handle);
+	struct winusb_device_handle_priv *handle_priv = get_winusb_device_handle_priv(dev_handle);
 	struct winusb_device_priv *priv = usbi_get_device_priv(dev_handle->dev);
 	int current_interface;