diff --git a/libusb/core.c b/libusb/core.c
index 009d0c8..00af3eb 100644
--- a/libusb/core.c
+++ b/libusb/core.c
@@ -1639,7 +1639,7 @@
 	int configuration)
 {
 	usbi_dbg("configuration %d", configuration);
-	if (configuration < -1 || configuration > UINT8_MAX)
+	if (configuration < -1 || configuration > (int)UINT8_MAX)
 		return LIBUSB_ERROR_INVALID_PARAM;
 	return usbi_backend.set_configuration(dev_handle, configuration);
 }
@@ -1768,7 +1768,7 @@
 		interface_number, alternate_setting);
 	if (interface_number < 0 || interface_number >= USB_MAXINTERFACES)
 		return LIBUSB_ERROR_INVALID_PARAM;
-	if (alternate_setting < 0 || alternate_setting > UINT8_MAX)
+	if (alternate_setting < 0 || alternate_setting > (int)UINT8_MAX)
 		return LIBUSB_ERROR_INVALID_PARAM;
 
 	usbi_mutex_lock(&dev_handle->lock);
diff --git a/libusb/os/haiku_usb_backend.cpp b/libusb/os/haiku_usb_backend.cpp
index 9eda263..2b6ad71 100644
--- a/libusb/os/haiku_usb_backend.cpp
+++ b/libusb/os/haiku_usb_backend.cpp
@@ -26,7 +26,7 @@
 
 #include "haiku_usb.h"
 
-int _errno_to_libusb(int status)
+static int _errno_to_libusb(int status)
 {
 	return status;
 }
@@ -127,7 +127,7 @@
 			int i;
 			usb_iso_packet_descriptor *packetDescriptors = new usb_iso_packet_descriptor[fLibusbTransfer->num_iso_packets];
 			for (i = 0; i < fLibusbTransfer->num_iso_packets; i++) {
-				if ((int16)(fLibusbTransfer->iso_packet_desc[i]).length != (fLibusbTransfer->iso_packet_desc[i]).length) {
+				if ((fLibusbTransfer->iso_packet_desc[i]).length > (unsigned int)INT16_MAX) {
 					fUsbiTransfer->transferred = -1;
 					usbi_err(TRANSFER_CTX(fLibusbTransfer), "failed isochronous transfer");
 					break;
@@ -222,9 +222,9 @@
 
 USBDeviceHandle::USBDeviceHandle(USBDevice *dev)
 	:
-	fTransfersThread(-1),
 	fUSBDevice(dev),
 	fClaimedInterfaces(0),
+	fTransfersThread(-1),
 	fInitCheck(false)
 {
 	fRawFD = open(dev->Location(), O_RDWR | O_CLOEXEC);
@@ -295,7 +295,7 @@
 		usbi_err(NULL, "Error retrieving active alternate interface");
 		return _errno_to_libusb(command.alternate.status);
 	}
-	if (command.alternate.alternate_info == alt) {
+	if (command.alternate.alternate_info == (uint32)alt) {
 		usbi_dbg("Setting alternate interface successful");
 		return LIBUSB_SUCCESS;
 	}
@@ -329,10 +329,10 @@
 
 USBDevice::USBDevice(const char *path)
 	:
-	fPath(NULL),
-	fActiveConfiguration(0),	//0?
-	fConfigurationDescriptors(NULL),
 	fClaimedInterfaces(0),
+	fConfigurationDescriptors(NULL),
+	fActiveConfiguration(0),	//0?
+	fPath(NULL),
 	fEndpointToIndex(NULL),
 	fEndpointToInterface(NULL),
 	fInitCheck(false)
diff --git a/libusb/os/haiku_usb_raw.cpp b/libusb/os/haiku_usb_raw.cpp
index f48c507..a9fb6b8 100644
--- a/libusb/os/haiku_usb_raw.cpp
+++ b/libusb/os/haiku_usb_raw.cpp
@@ -35,6 +35,7 @@
 static int
 haiku_init(struct libusb_context *ctx)
 {
+	UNUSED(ctx);
 	if (atomic_add(&gInitCount, 1) == 0)
 		return gUsbRoster.Start();
 	return LIBUSB_SUCCESS;
diff --git a/libusb/os/netbsd_usb.c b/libusb/os/netbsd_usb.c
index 485208d..2a1359b 100644
--- a/libusb/os/netbsd_usb.c
+++ b/libusb/os/netbsd_usb.c
@@ -227,13 +227,13 @@
 {
 	struct device_priv *dpriv = usbi_get_device_priv(dev);
 
-	len = MIN(len, UGETW(dpriv->cdesc->wTotalLength));
+	len = MIN(len, (size_t)UGETW(dpriv->cdesc->wTotalLength));
 
-	usbi_dbg("len %d", len);
+	usbi_dbg("len %zu", len);
 
 	memcpy(buf, dpriv->cdesc, len);
 
-	return len;
+	return (int)len;
 }
 
 int
@@ -244,7 +244,7 @@
 	struct usb_full_desc ufd;
 	int fd, err;
 
-	usbi_dbg("index %d, len %d", idx, len);
+	usbi_dbg("index %u, len %zu", idx, len);
 
 	/* A config descriptor may be requested before opening the device */
 	if (dpriv->fd >= 0) {
@@ -269,7 +269,7 @@
 	if (dpriv->fd < 0)
 		close(fd);
 
-	return len;
+	return (int)len;
 }
 
 int
@@ -306,6 +306,8 @@
 	struct handle_priv *hpriv = usbi_get_device_handle_priv(handle);
 	int i;
 
+	UNUSED(iface);
+
 	for (i = 0; i < USB_MAX_ENDPOINTS; i++)
 		hpriv->endpoints[i] = -1;
 
@@ -318,6 +320,8 @@
 	struct handle_priv *hpriv = usbi_get_device_handle_priv(handle);
 	int i;
 
+	UNUSED(iface);
+
 	for (i = 0; i < USB_MAX_ENDPOINTS; i++)
 		if (hpriv->endpoints[i] >= 0)
 			close(hpriv->endpoints[i]);
@@ -379,13 +383,11 @@
 netbsd_submit_transfer(struct usbi_transfer *itransfer)
 {
 	struct libusb_transfer *transfer;
-	struct handle_priv *hpriv;
 	int err = 0;
 
 	usbi_dbg(" ");
 
 	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
-	hpriv = usbi_get_device_handle_priv(transfer->dev_handle);
 
 	switch (transfer->type) {
 	case LIBUSB_TRANSFER_TYPE_CONTROL:
@@ -424,6 +426,8 @@
 int
 netbsd_cancel_transfer(struct usbi_transfer *itransfer)
 {
+	UNUSED(itransfer);
+
 	usbi_dbg(" ");
 
 	return (LIBUSB_ERROR_NOT_SUPPORTED);
diff --git a/libusb/os/openbsd_usb.c b/libusb/os/openbsd_usb.c
index 41550b0..42cfbd5 100644
--- a/libusb/os/openbsd_usb.c
+++ b/libusb/os/openbsd_usb.c
@@ -260,13 +260,13 @@
 {
 	struct device_priv *dpriv = usbi_get_device_priv(dev);
 
-	len = MIN(len, UGETW(dpriv->cdesc->wTotalLength));
+	len = MIN(len, (size_t)UGETW(dpriv->cdesc->wTotalLength));
 
 	usbi_dbg("len %zu", len);
 
 	memcpy(buf, dpriv->cdesc, len);
 
-	return (len);
+	return ((int)len);
 }
 
 int
@@ -294,7 +294,7 @@
 	}
 	close(fd);
 
-	return (len);
+	return ((int)len);
 }
 
 int
@@ -331,6 +331,8 @@
 	struct handle_priv *hpriv = usbi_get_device_handle_priv(handle);
 	int i;
 
+	UNUSED(iface);
+
 	for (i = 0; i < USB_MAX_ENDPOINTS; i++)
 		hpriv->endpoints[i] = -1;
 
@@ -343,6 +345,8 @@
 	struct handle_priv *hpriv = usbi_get_device_handle_priv(handle);
 	int i;
 
+	UNUSED(iface);
+
 	for (i = 0; i < USB_MAX_ENDPOINTS; i++)
 		if (hpriv->endpoints[i] >= 0)
 			close(hpriv->endpoints[i]);
@@ -416,13 +420,11 @@
 obsd_submit_transfer(struct usbi_transfer *itransfer)
 {
 	struct libusb_transfer *transfer;
-	struct handle_priv *hpriv;
 	int err = 0;
 
 	usbi_dbg(" ");
 
 	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
-	hpriv = usbi_get_device_handle_priv(transfer->dev_handle);
 
 	switch (transfer->type) {
 	case LIBUSB_TRANSFER_TYPE_CONTROL:
@@ -461,6 +463,8 @@
 int
 obsd_cancel_transfer(struct usbi_transfer *itransfer)
 {
+	UNUSED(itransfer);
+
 	usbi_dbg(" ");
 
 	return (LIBUSB_ERROR_NOT_SUPPORTED);
diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index 5dac176..f15a1f1 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11511
+#define LIBUSB_NANO 11512