diff --git a/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java b/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java
index a43fb7c..c10e6f6 100644
--- a/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java
+++ b/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java
@@ -14,6 +14,7 @@ import android.content.Context;
 import android.hardware.usb.UsbDevice;
 import android.hardware.usb.UsbDeviceConnection;
 import android.hardware.usb.UsbManager;
+import android.os.Process;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.runner.AndroidJUnit4;
 import android.util.Log;
@@ -1025,6 +1026,8 @@ public class DeviceTest {
         usb.ioManager = new SerialInputOutputManager(usb.serialPort, usb);
         assertEquals(usb, usb.ioManager.getListener());
 
+        usb.ioManager.setThreadPriority(Process.THREAD_PRIORITY_AUDIO);
+
         assertEquals(0, usb.ioManager.getReadTimeout());
         usb.ioManager.setReadTimeout(10);
         assertEquals(10, usb.ioManager.getReadTimeout());
@@ -1043,6 +1046,10 @@ public class DeviceTest {
         usb.setParameters(19200, 8, 1, UsbSerialPort.PARITY_NONE);
         telnet.setParameters(19200, 8, 1, UsbSerialPort.PARITY_NONE);
         usb.waitForIoManagerStarted();
+        try {
+            usb.ioManager.setThreadPriority(Process.THREAD_PRIORITY_LOWEST);
+            fail("setThreadPriority IllegalStateException expected");
+        } catch (IllegalStateException ignored) {}
         try {
             usb.ioManager.setReadTimeout(20);
             fail("setReadTimeout IllegalStateException expected");
diff --git a/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/util/UsbWrapper.java b/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/util/UsbWrapper.java
index 7dddfd4..a2e1739 100644
--- a/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/util/UsbWrapper.java
+++ b/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/util/UsbWrapper.java
@@ -35,7 +35,6 @@ public class UsbWrapper implements SerialInputOutputManager.Listener {
 
     private final static int     USB_READ_WAIT = 500;
     private final static int     USB_WRITE_WAIT = 500;
-    private final static Integer SERIAL_INPUT_OUTPUT_MANAGER_THREAD_PRIORITY = Process.THREAD_PRIORITY_URGENT_AUDIO;
     private static final String TAG = UsbWrapper.class.getSimpleName();
 
     public enum OpenCloseFlags { NO_IOMANAGER_THREAD, NO_CONTROL_LINE_INIT, NO_DEVICE_CONNECTION };
@@ -157,14 +156,7 @@ public class UsbWrapper implements SerialInputOutputManager.Listener {
             serialPort.setRTS(true);
         }
         if(!flags.contains(OpenCloseFlags.NO_IOMANAGER_THREAD)) {
-            ioManager = new SerialInputOutputManager(serialPort, this) {
-                @Override
-                public void run() {
-                    if (SERIAL_INPUT_OUTPUT_MANAGER_THREAD_PRIORITY != null)
-                        Process.setThreadPriority(SERIAL_INPUT_OUTPUT_MANAGER_THREAD_PRIORITY);
-                    super.run();
-                }
-            };
+            ioManager = new SerialInputOutputManager(serialPort, this);
             ioManager.setReadTimeout(ioManagerTimeout);
             ioManager.setWriteTimeout(ioManagerTimeout);
             Executors.newSingleThreadExecutor().submit(ioManager);
diff --git a/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/util/SerialInputOutputManager.java b/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/util/SerialInputOutputManager.java
index fbd95de..001679e 100644
--- a/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/util/SerialInputOutputManager.java
+++ b/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/util/SerialInputOutputManager.java
@@ -6,6 +6,7 @@
 
 package com.hoho.android.usbserial.util;
 
+import android.os.Process;
 import android.util.Log;
 
 import com.hoho.android.usbserial.driver.UsbSerialPort;
@@ -42,6 +43,7 @@ public class SerialInputOutputManager implements Runnable {
         STOPPING
     }
 
+    private int mThreadPriority = Process.THREAD_PRIORITY_URGENT_AUDIO;
     private State mState = State.STOPPED; // Synchronized by 'this'
     private Listener mListener; // Synchronized by 'this'
     private final UsbSerialPort mSerialPort;
@@ -75,6 +77,17 @@ public class SerialInputOutputManager implements Runnable {
         return mListener;
     }
 
+    /**
+     * setThreadPriority. By default use higher priority than UI thread to prevent data loss
+     *
+     * @param threadPriority  see {@link Process#setThreadPriority(int)}
+     * */
+    public void setThreadPriority(int threadPriority) {
+        if (mState != State.STOPPED)
+            throw new IllegalStateException("threadPriority only configurable before SerialInputOutputManager is started");
+        mThreadPriority = threadPriority;
+    }
+
     /**
      * read/write timeout
      */
@@ -154,6 +167,9 @@ public class SerialInputOutputManager implements Runnable {
      */
     @Override
     public void run() {
+        if(mThreadPriority != Process.THREAD_PRIORITY_DEFAULT)
+            setThreadPriority(mThreadPriority);
+
         synchronized (this) {
             if (getState() != State.STOPPED) {
                 throw new IllegalStateException("Already running");