diff --git a/packages/SettingsLib/src/com/android/settingslib/wifi/WifiTracker.java b/packages/SettingsLib/src/com/android/settingslib/wifi/WifiTracker.java
index c6179943b4d31..0ec16ae268432 100644
--- a/packages/SettingsLib/src/com/android/settingslib/wifi/WifiTracker.java
+++ b/packages/SettingsLib/src/com/android/settingslib/wifi/WifiTracker.java
@@ -41,7 +41,6 @@ import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
 import android.provider.Settings;
-import android.support.annotation.WorkerThread;
 import android.util.ArraySet;
 import android.util.Log;
 import android.util.SparseArray;
@@ -211,7 +210,7 @@ public class WifiTracker {
 
         mNetworkScoreManager = networkScoreManager;
 
-        mScoreCache = new WifiNetworkScoreCache(context, new CacheListener(mWorkHandler) {
+        mScoreCache = new WifiNetworkScoreCache(context, new CacheListener(mMainHandler) {
             @Override
             public void networkCacheUpdated(List<ScoredNetwork> networks) {
                 if (Log.isLoggable(TAG, Log.VERBOSE)) {
@@ -282,12 +281,7 @@ public class WifiTracker {
      * then forceUpdate() must be called to populate getAccessPoints().
      */
     public void startTracking() {
-        mWorkHandler.post(new Runnable() {
-            @Override
-            public void run() {
-                registerScoreCache();
-            }
-        });
+        registerScoreCache();
 
         mContext.getContentResolver().registerContentObserver(
                 Settings.Global.getUriFor(Settings.Global.NETWORK_SCORING_UI_ENABLED),
@@ -305,7 +299,6 @@ public class WifiTracker {
         }
     }
 
-    @WorkerThread
     private void registerScoreCache() {
         mNetworkScoreManager.registerNetworkScoreCache(
                 NetworkKey.TYPE_WIFI,
@@ -341,20 +334,17 @@ public class WifiTracker {
         }
         pauseScanning();
 
-        mWorkHandler.post(new Runnable() {
-            @Override
-            public void run() {
-                unregisterAndClearScoreCache();
-            }
-        });
+        unregisterAndClearScoreCache();
+
         mContext.getContentResolver().unregisterContentObserver(mObserver);
     }
 
-    @WorkerThread
     private void unregisterAndClearScoreCache() {
-        mRequestedScores.clear();
         mNetworkScoreManager.unregisterNetworkScoreCache(NetworkKey.TYPE_WIFI, mScoreCache);
         mScoreCache.clearScores();
+
+        // Clear the scores on the work handler to avoid concurrent modification exceptions
+        mWorkHandler.post(() -> mRequestedScores.clear());
     }
 
     /**
diff --git a/packages/SettingsLib/tests/integ/src/com/android/settingslib/wifi/WifiTrackerTest.java b/packages/SettingsLib/tests/integ/src/com/android/settingslib/wifi/WifiTrackerTest.java
index 08736c77c409a..0f220aaf5574e 100644
--- a/packages/SettingsLib/tests/integ/src/com/android/settingslib/wifi/WifiTrackerTest.java
+++ b/packages/SettingsLib/tests/integ/src/com/android/settingslib/wifi/WifiTrackerTest.java
@@ -72,7 +72,7 @@ import java.util.concurrent.TimeUnit;
 public class WifiTrackerTest {
 
     private static final String TAG = "WifiTrackerTest";
-    private static final int LATCH_TIMEOUT = 2000;
+    private static final int LATCH_TIMEOUT = 4000;
 
     private static final String SSID_1 = "ssid1";
     private static final String BSSID_1 = "00:00:00:00:00:00";
@@ -226,7 +226,7 @@ public class WifiTrackerTest {
 
         mAccessPointsChangedLatch = new CountDownLatch(1);
         sendScanResultsAndProcess(tracker);
-        mAccessPointsChangedLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS);
+        assertTrue(mAccessPointsChangedLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS));
 
         return tracker;
     }
@@ -242,7 +242,8 @@ public class WifiTrackerTest {
                     true,
                     mockWifiManager,
                     mockConnectivityManager,
-                        mockNetworkScoreManager, mMainLooper
+                    mockNetworkScoreManager,
+                    mMainLooper
                 );
 
         return tracker;
@@ -257,7 +258,7 @@ public class WifiTrackerTest {
                 latch.countDown();
             }
         });
-        latch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS);
+        assertTrue("Latch timed out", latch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS));
     }
 
     private void sendScanResultsAndProcess(WifiTracker tracker) throws InterruptedException {
@@ -265,7 +266,8 @@ public class WifiTrackerTest {
         Intent i = new Intent(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
         tracker.mReceiver.onReceive(mContext, i);
 
-        mAccessPointsChangedLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS);
+        assertTrue("Latch timed out",
+                mAccessPointsChangedLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS));
     }
 
     private void updateScores() {
@@ -348,7 +350,7 @@ public class WifiTrackerTest {
         // Test unregister
         tracker.stopTracking();
 
-        latch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS);
+        assertTrue("Latch timed out", latch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS));
         verify(mockNetworkScoreManager)
                 .unregisterNetworkScoreCache(NetworkKey.TYPE_WIFI, scoreCache);
     }
@@ -359,12 +361,15 @@ public class WifiTrackerTest {
         WifiTracker tracker =  createTrackerAndInjectInitialScanResults();
 
         tracker.stopTracking();
+        android.util.Log.d("WifiTrackerTest", "Clearing previously captured requested keys");
         mRequestedKeys.clear();
 
-        mRequestScoresLatch = new CountDownLatch(2);
+        mRequestScoresLatch = new CountDownLatch(1);
         startTracking(tracker);
-        mRequestScoresLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS);
+        assertTrue("Latch timed out",
+                mRequestScoresLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS));
 
+        android.util.Log.d("WifiTrackerTest", "requested keys: " + mRequestedKeys);
         assertTrue(mRequestedKeys.contains(NETWORK_KEY_1));
         assertTrue(mRequestedKeys.contains(NETWORK_KEY_2));
     }
@@ -379,6 +384,8 @@ public class WifiTrackerTest {
     }
 
     private void updateScoresAndWaitForAccessPointsChangedCallback() throws InterruptedException {
+        // Updating scores can happen together or one after the other, so the latch countdown is set
+        // to 2.
         mAccessPointsChangedLatch = new CountDownLatch(2);
         updateScores();
         mAccessPointsChangedLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS);
@@ -462,6 +469,8 @@ public class WifiTrackerTest {
 
     @Test
     public void scoresShouldBeRequestedForNewScanResultOnly()  throws InterruptedException {
+        // Scores can be requested together or serially depending on how the scan results are
+        // processed.
         mRequestScoresLatch = new CountDownLatch(2);
         WifiTracker tracker = createTrackerAndInjectInitialScanResults();
         mRequestScoresLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS);
@@ -484,9 +493,24 @@ public class WifiTrackerTest {
 
         mRequestScoresLatch = new CountDownLatch(1);
         sendScanResultsAndProcess(tracker);
-        mRequestScoresLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS);
+        assertTrue(mRequestScoresLatch.await(LATCH_TIMEOUT, TimeUnit.MILLISECONDS));
 
         assertEquals(1, mRequestedKeys.size());
         assertTrue(mRequestedKeys.contains(new NetworkKey(new WifiKey('"' + ssid + '"', bssid))));
     }
+
+    @Test
+    public void scoreCacheAndListenerShouldBeUnregisteredWhenStopTrackingIsCalled() throws Exception
+    {
+        WifiTracker tracker =  createTrackerAndInjectInitialScanResults();
+        WifiNetworkScoreCache cache = mScoreCacheCaptor.getValue();
+
+        tracker.stopTracking();
+        verify(mockNetworkScoreManager).unregisterNetworkScoreCache(NetworkKey.TYPE_WIFI, cache);
+
+        // Verify listener is unregistered so updating a score does not throw an error by posting
+        // a message to the dead work handler
+        mWorkerThread.quit();
+        updateScores();
+    }
 }