diff --git a/core/java/android/app/NotificationChannelGroup.java b/core/java/android/app/NotificationChannelGroup.java
index 3341b915931a3..68cac27cb7cac 100644
--- a/core/java/android/app/NotificationChannelGroup.java
+++ b/core/java/android/app/NotificationChannelGroup.java
@@ -64,7 +64,7 @@ public final class NotificationChannelGroup implements Parcelable {
             mId = null;
         }
         mName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in);
-        in.readList(mChannels, NotificationChannel.class.getClassLoader());
+        in.readParcelableList(mChannels, NotificationChannel.class.getClassLoader());
     }
 
     @Override
diff --git a/services/core/java/com/android/server/notification/RankingConfig.java b/services/core/java/com/android/server/notification/RankingConfig.java
index 2e35e3dbc5e1d..6a0072216f700 100644
--- a/services/core/java/com/android/server/notification/RankingConfig.java
+++ b/services/core/java/com/android/server/notification/RankingConfig.java
@@ -19,6 +19,8 @@ import android.app.NotificationChannel;
 import android.app.NotificationChannelGroup;
 import android.content.pm.ParceledListSlice;
 
+import java.util.Collection;
+
 public interface RankingConfig {
 
     void setImportance(String packageName, int uid, int importance);
@@ -26,6 +28,8 @@ public interface RankingConfig {
     void setShowBadge(String packageName, int uid, boolean showBadge);
     boolean canShowBadge(String packageName, int uid);
 
+    Collection<NotificationChannelGroup> getNotificationChannelGroups(String pkg,
+            int uid);
     void createNotificationChannelGroup(String pkg, int uid, NotificationChannelGroup group,
             boolean fromTargetApp);
     ParceledListSlice<NotificationChannelGroup> getNotificationChannelGroups(String pkg,
diff --git a/services/core/java/com/android/server/notification/RankingHelper.java b/services/core/java/com/android/server/notification/RankingHelper.java
index 01cca2d0f35ca..5b6ac692aede1 100644
--- a/services/core/java/com/android/server/notification/RankingHelper.java
+++ b/services/core/java/com/android/server/notification/RankingHelper.java
@@ -47,6 +47,7 @@ import org.xmlpull.v1.XmlSerializer;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -691,13 +692,28 @@ public class RankingHelper implements RankingConfig {
                 }
             }
         }
-        groups.addAll(r.groups.values());
+        for (NotificationChannelGroup group : r.groups.values()) {
+            if (group.getChannels().size() > 0) {
+                groups.add(group);
+            }
+        }
         if (nonGrouped.getChannels().size() > 0) {
             groups.add(nonGrouped);
         }
         return new ParceledListSlice<>(groups);
     }
 
+    @Override
+    @VisibleForTesting
+    public Collection<NotificationChannelGroup> getNotificationChannelGroups(String pkg,
+            int uid) {
+        Record r = getRecord(pkg, uid);
+        if (r == null) {
+            return new ArrayList<>();
+        }
+        return r.groups.values();
+    }
+
     @Override
     public ParceledListSlice<NotificationChannel> getNotificationChannels(String pkg, int uid,
             boolean includeDeleted) {
diff --git a/services/tests/notification/src/com/android/server/notification/RankingHelperTest.java b/services/tests/notification/src/com/android/server/notification/RankingHelperTest.java
index 5be6e91ba8634..b53ec4548393a 100644
--- a/services/tests/notification/src/com/android/server/notification/RankingHelperTest.java
+++ b/services/tests/notification/src/com/android/server/notification/RankingHelperTest.java
@@ -805,7 +805,7 @@ public class RankingHelperTest {
     public void testCreateGroup() throws Exception {
         NotificationChannelGroup ncg = new NotificationChannelGroup("group1", "name1");
         mHelper.createNotificationChannelGroup(pkg, uid, ncg, true);
-        assertEquals(ncg, mHelper.getNotificationChannelGroups(pkg, uid, false).getList().get(0));
+        assertEquals(ncg, mHelper.getNotificationChannelGroups(pkg, uid).iterator().next());
     }
 
     @Test
@@ -834,6 +834,8 @@ public class RankingHelperTest {
 
     @Test
     public void testGetChannelGroups() throws Exception {
+        NotificationChannelGroup unused = new NotificationChannelGroup("unused", "s");
+        mHelper.createNotificationChannelGroup(pkg, uid, unused, true);
         NotificationChannelGroup ncg = new NotificationChannelGroup("group1", "name1");
         mHelper.createNotificationChannelGroup(pkg, uid, ncg, true);
         NotificationChannelGroup ncg2 = new NotificationChannelGroup("group2", "name2");