diff --git a/third_party/libusb/src/libusb/core.c b/third_party/libusb/src/libusb/core.c
index 34ed488216641..be7e479c29aa9 100644
--- a/third_party/libusb/src/libusb/core.c
+++ b/third_party/libusb/src/libusb/core.c
@@ -1538,12 +1538,12 @@ int API_EXPORTED libusb_claim_interface(libusb_device_handle *dev,
 		return LIBUSB_ERROR_NO_DEVICE;
 
 	usbi_mutex_lock(&dev->lock);
-	if (dev->claimed_interfaces & (1 << interface_number))
+	if (dev->claimed_interfaces & (1U << interface_number))
 		goto out;
 
 	r = usbi_backend->claim_interface(dev, interface_number);
 	if (r == 0)
-		dev->claimed_interfaces |= 1 << interface_number;
+		dev->claimed_interfaces |= 1U << interface_number;
 
 out:
 	usbi_mutex_unlock(&dev->lock);
@@ -1579,14 +1579,14 @@ int API_EXPORTED libusb_release_interface(libusb_device_handle *dev,
 		return LIBUSB_ERROR_INVALID_PARAM;
 
 	usbi_mutex_lock(&dev->lock);
-	if (!(dev->claimed_interfaces & (1 << interface_number))) {
+	if (!(dev->claimed_interfaces & (1U << interface_number))) {
 		r = LIBUSB_ERROR_NOT_FOUND;
 		goto out;
 	}
 
 	r = usbi_backend->release_interface(dev, interface_number);
 	if (r == 0)
-		dev->claimed_interfaces &= ~(1 << interface_number);
+		dev->claimed_interfaces &= ~(1U << interface_number);
 
 out:
 	usbi_mutex_unlock(&dev->lock);
@@ -1628,7 +1628,7 @@ int API_EXPORTED libusb_set_interface_alt_setting(libusb_device_handle *dev,
 		return LIBUSB_ERROR_NO_DEVICE;
 	}
 
-	if (!(dev->claimed_interfaces & (1 << interface_number))) {
+	if (!(dev->claimed_interfaces & (1U << interface_number))) {
 		usbi_mutex_unlock(&dev->lock);
 		return LIBUSB_ERROR_NOT_FOUND;
 	}
diff --git a/third_party/libusb/src/libusb/os/darwin_usb.c b/third_party/libusb/src/libusb/os/darwin_usb.c
index 4d4024aaeee6a..0f5da1dd670b0 100644
--- a/third_party/libusb/src/libusb/os/darwin_usb.c
+++ b/third_party/libusb/src/libusb/os/darwin_usb.c
@@ -165,7 +165,7 @@ static int ep_to_pipeRef(struct libusb_device_handle *dev_handle, uint8_t ep, ui
   for (iface = 0 ; iface < USB_MAXINTERFACES ; iface++) {
     cInterface = &priv->interfaces[iface];
 
-    if (dev_handle->claimed_interfaces & (1 << iface)) {
+    if (dev_handle->claimed_interfaces & (1U << iface)) {
       for (i = 0 ; i < cInterface->num_endpoints ; i++) {
         if (cInterface->endpoint_addrs[i] == ep) {
           *pipep = i + 1;
@@ -665,7 +665,7 @@ static int darwin_cache_device_descriptor (struct libusb_context *ctx, struct da
       (void)(*device)->GetUSBDeviceInformation (device, &info);
 
       /* note that the device was suspended */
-      if (info & (1 << kUSBInformationDeviceIsSuspendedBit) || 0 == info)
+      if (info & (1U << kUSBInformationDeviceIsSuspendedBit) || 0 == info)
         try_unsuspend = 1;
 #endif
 
@@ -995,7 +995,7 @@ static void darwin_close (struct libusb_device_handle *dev_handle) {
 
   /* make sure all interfaces are released */
   for (i = 0 ; i < USB_MAXINTERFACES ; i++)
-    if (dev_handle->claimed_interfaces & (1 << i))
+    if (dev_handle->claimed_interfaces & (1U << i))
       libusb_release_interface (dev_handle, i);
 
   if (0 == dpriv->open_count) {
@@ -1042,7 +1042,7 @@ static int darwin_set_configuration(struct libusb_device_handle *dev_handle, int
   /* Setting configuration will invalidate the interface, so we need
      to reclaim it. First, dispose of existing interfaces, if any. */
   for (i = 0 ; i < USB_MAXINTERFACES ; i++)
-    if (dev_handle->claimed_interfaces & (1 << i))
+    if (dev_handle->claimed_interfaces & (1U << i))
       darwin_release_interface (dev_handle, i);
 
   kresult = (*(dpriv->device))->SetConfiguration (dpriv->device, config);
@@ -1051,7 +1051,7 @@ static int darwin_set_configuration(struct libusb_device_handle *dev_handle, int
 
   /* Reclaim any interfaces. */
   for (i = 0 ; i < USB_MAXINTERFACES ; i++)
-    if (dev_handle->claimed_interfaces & (1 << i))
+    if (dev_handle->claimed_interfaces & (1U << i))
       darwin_claim_interface (dev_handle, i);
 
   dpriv->active_config = config;