diff --git a/omriusb/src/main/java/org/omri/radio/impl/UsbHelper.java b/omriusb/src/main/java/org/omri/radio/impl/UsbHelper.java
index ec24cc4..1625996 100644
--- a/omriusb/src/main/java/org/omri/radio/impl/UsbHelper.java
+++ b/omriusb/src/main/java/org/omri/radio/impl/UsbHelper.java
@@ -83,13 +83,29 @@ private UsbHelper(Context context) {
 
 		if(mContext != null) {
 			mUsbManager = (UsbManager)mContext.getSystemService(Context.USB_SERVICE);
-			mUsbPermissionIntent = PendingIntent.getBroadcast(mContext, 0, new Intent(ACTION_USB_PERMISSION), 0);
+			// Android 12 (S, API 31) requires PendingIntent flags to explicitly declare mutability.
+			// UsbManager.requestPermission() needs to populate EXTRA_DEVICE and
+			// EXTRA_PERMISSION_GRANTED on the intent before broadcasting it back to us, which
+			// requires FLAG_MUTABLE. (FLAG_IMMUTABLE would deliver an empty broadcast and the
+			// permission flow would silently fail.)
+			int piFlags = PendingIntent.FLAG_UPDATE_CURRENT;
+			if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.S) {
+				piFlags |= PendingIntent.FLAG_MUTABLE;
+			}
+			mUsbPermissionIntent = PendingIntent.getBroadcast(mContext, 0, new Intent(ACTION_USB_PERMISSION), piFlags);
 
 			IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
 			filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
 			filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
 
-			mContext.registerReceiver(mUsbBroadcastReceiver, filter);
+			// Android 13 (TIRAMISU, API 33) requires runtime-registered receivers to specify
+			// export-ness. ACTION_USB_PERMISSION is delivered by the system to our own process,
+			// so RECEIVER_NOT_EXPORTED is correct.
+			if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.TIRAMISU) {
+				mContext.registerReceiver(mUsbBroadcastReceiver, filter, Context.RECEIVER_NOT_EXPORTED);
+			} else {
+				mContext.registerReceiver(mUsbBroadcastReceiver, filter);
+			}
 			created();
 		}
 	}
@@ -228,6 +244,20 @@ void removeDevice(UsbDevice remDev) {
 		public void onReceive(Context context, Intent intent) {
 			UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
 			String action = intent.getAction();
+			if (action == null) {
+				if (DEBUG) Log.w(TAG, "Received broadcast with null action; ignoring");
+				return;
+			}
+			if (device == null) {
+				// Some Android builds deliver a USB_PERMISSION broadcast with EXTRA_DEVICE missing
+				// (e.g. when the system retracts a pending request). Without a device handle there
+				// is nothing meaningful to do; clearing pending state avoids getting stuck.
+				if (DEBUG) Log.w(TAG, "Received " + action + " with null EXTRA_DEVICE; ignoring");
+				if (ACTION_USB_PERMISSION.equals(action)) {
+					mPermissionPending = false;
+				}
+				return;
+			}
 			synchronized (this) {
 				if (ACTION_USB_PERMISSION.equals(action)) {
 					if(DEBUG)Log.d(TAG, "Received Permission request: " + action);