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 df82d5d..f39d587 100644
--- a/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java
+++ b/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java
@@ -1485,6 +1485,17 @@ public class DeviceTest {
         assertFalse("iomanager threads", usb.hasIoManagerThreads());
         assertNull(usb.ioManager);
         assertEquals(SerialInputOutputManager.State.STOPPED, ioManager.getState());
+
+        usb.open();
+        ioManager = usb.ioManager;
+        assertEquals(SerialInputOutputManager.State.RUNNING, usb.ioManager.getState());
+        usb.serialPort.close(); // stop before ioManager
+        for (int i = 0; i < 100 && usb.hasIoManagerThreads(); i++) {
+            Thread.sleep(1);
+        }
+        assertFalse("iomanager threads", usb.hasIoManagerThreads());
+        assertEquals(SerialInputOutputManager.State.STOPPED, usb.ioManager.getState());
+
         SerialInputOutputManager.DEBUG = false;
     }
 
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 c22a2b8..c0d50da 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
@@ -183,7 +183,7 @@ public class SerialInputOutputManager {
     public void stop() {
         if(mState.compareAndSet(State.RUNNING, State.STOPPING)) {
             synchronized (mWriteBufferLock) {
-                mWriteBufferLock.notifyAll(); // Wake up any waiting thread to check the stop condition
+                mWriteBufferLock.notifyAll(); // wake up write thread to check the stop condition
             }
             Log.i(TAG, "Stop requested");
         }
@@ -250,10 +250,12 @@ public class SerialInputOutputManager {
             }
             notifyErrorListener(e);
         } finally {
-            if (!mState.compareAndSet(State.RUNNING, State.STOPPING)) {
-                if (mState.compareAndSet(State.STOPPING, State.STOPPED)) {
-                    Log.i(TAG, "runRead: Stopped mState=" + getState());
+            if (mState.compareAndSet(State.RUNNING, State.STOPPING)) {
+                synchronized (mWriteBufferLock) {
+                    mWriteBufferLock.notifyAll(); // wake up write thread to check the stop condition
                 }
+            } else if (mState.compareAndSet(State.STOPPING, State.STOPPED)) {
+                Log.i(TAG, "runRead: Stopped mState=" + getState());
             }
         }
     }