diff --git a/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java b/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
index 0cd065169713a..1e67769277da9 100644
--- a/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
+++ b/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
@@ -117,10 +117,7 @@ public class UpstreamNetworkMonitorTest {
 
         mUNM.registerMobileNetworkRequest();
         assertTrue(mUNM.mobileNetworkRequested());
-        assertEquals(1, mCM.requested.size());
-        assertEquals(1, mCM.legacyTypeMap.size());
-        assertEquals(Integer.valueOf(TYPE_MOBILE_HIPRI),
-                mCM.legacyTypeMap.values().iterator().next());
+        assertUpstreamTypeRequested(TYPE_MOBILE_HIPRI);
         assertFalse(mCM.isDunRequested());
 
         mUNM.stop();
@@ -143,10 +140,7 @@ public class UpstreamNetworkMonitorTest {
 
         mUNM.registerMobileNetworkRequest();
         assertTrue(mUNM.mobileNetworkRequested());
-        assertEquals(1, mCM.requested.size());
-        assertEquals(1, mCM.legacyTypeMap.size());
-        assertEquals(Integer.valueOf(TYPE_MOBILE_DUN),
-                mCM.legacyTypeMap.values().iterator().next());
+        assertUpstreamTypeRequested(TYPE_MOBILE_DUN);
         assertTrue(mCM.isDunRequested());
 
         mUNM.stop();
@@ -154,6 +148,38 @@ public class UpstreamNetworkMonitorTest {
         assertTrue(mCM.hasNoCallbacks());
     }
 
+    @Test
+    public void testUpdateMobileRequiredDun() throws Exception {
+        mUNM.start();
+
+        // Test going from no-DUN to DUN correctly re-registers callbacks.
+        mUNM.updateMobileRequiresDun(false);
+        mUNM.registerMobileNetworkRequest();
+        assertTrue(mUNM.mobileNetworkRequested());
+        assertUpstreamTypeRequested(TYPE_MOBILE_HIPRI);
+        assertFalse(mCM.isDunRequested());
+        mUNM.updateMobileRequiresDun(true);
+        assertTrue(mUNM.mobileNetworkRequested());
+        assertUpstreamTypeRequested(TYPE_MOBILE_DUN);
+        assertTrue(mCM.isDunRequested());
+
+        // Test going from DUN to no-DUN correctly re-registers callbacks.
+        mUNM.updateMobileRequiresDun(false);
+        assertTrue(mUNM.mobileNetworkRequested());
+        assertUpstreamTypeRequested(TYPE_MOBILE_HIPRI);
+        assertFalse(mCM.isDunRequested());
+
+        mUNM.stop();
+        assertFalse(mUNM.mobileNetworkRequested());
+    }
+
+    private void assertUpstreamTypeRequested(int upstreamType) throws Exception {
+        assertEquals(1, mCM.requested.size());
+        assertEquals(1, mCM.legacyTypeMap.size());
+        assertEquals(Integer.valueOf(upstreamType),
+                mCM.legacyTypeMap.values().iterator().next());
+    }
+
     private static class TestConnectivityManager extends ConnectivityManager {
         public Set<NetworkCallback> trackingDefault = new HashSet<>();
         public Map<NetworkCallback, NetworkRequest> listening = new HashMap<>();