diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 57573c24fe..f34b078c85 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -100,6 +100,8 @@
         `MediaMetadataCompat`
         ([#756](https://github.com/androidx/media/issues/756),
         [#802](https://github.com/androidx/media/issues/802)).
+    *   Fix broadcasting `notifyChildrenChanged` for legacy controllers
+        ([#644](https://github.com/androidx/media/issues/644)).
 *   UI:
     *   Fix issue where forward and rewind buttons are not visible when used
         with Material Design in a BottomSheetDialogFragment
diff --git a/libraries/session/src/main/java/androidx/media3/session/MediaLibrarySessionImpl.java b/libraries/session/src/main/java/androidx/media3/session/MediaLibrarySessionImpl.java
index 27dfad70c4..c6c8aa7e32 100644
--- a/libraries/session/src/main/java/androidx/media3/session/MediaLibrarySessionImpl.java
+++ b/libraries/session/src/main/java/androidx/media3/session/MediaLibrarySessionImpl.java
@@ -256,12 +256,10 @@ import java.util.concurrent.Future;
 
   public void notifyChildrenChanged(
       String parentId, int itemCount, @Nullable LibraryParams params) {
-    dispatchRemoteControllerTaskWithoutReturn(
-        (callback, seq) -> {
-          if (isSubscribed(callback, parentId)) {
-            callback.onChildrenChanged(seq, parentId, itemCount, params);
-          }
-        });
+    List<ControllerInfo> connectedControllers = instance.getConnectedControllers();
+    for (int i = 0; i < connectedControllers.size(); i++) {
+      notifyChildrenChanged(connectedControllers.get(i), parentId, itemCount, params);
+    }
   }
 
   public void notifyChildrenChanged(
diff --git a/libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaBrowserCompatWithMediaLibraryServiceTest.java b/libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaBrowserCompatWithMediaLibraryServiceTest.java
index cd5bf3c205..effbead386 100644
--- a/libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaBrowserCompatWithMediaLibraryServiceTest.java
+++ b/libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaBrowserCompatWithMediaLibraryServiceTest.java
@@ -19,6 +19,7 @@ import static androidx.media.utils.MediaConstants.BROWSER_SERVICE_EXTRAS_KEY_SEA
 import static androidx.media3.session.MediaConstants.EXTRAS_KEY_COMPLETION_STATUS;
 import static androidx.media3.session.MediaConstants.EXTRAS_VALUE_COMPLETION_STATUS_PARTIALLY_PLAYED;
 import static androidx.media3.session.MockMediaLibraryService.CONNECTION_HINTS_CUSTOM_LIBRARY_ROOT;
+import static androidx.media3.session.MockMediaLibraryService.createNotifyChildrenChangedBundle;
 import static androidx.media3.test.session.common.CommonConstants.METADATA_ARTWORK_URI;
 import static androidx.media3.test.session.common.CommonConstants.METADATA_DESCRIPTION;
 import static androidx.media3.test.session.common.CommonConstants.METADATA_EXTRA_KEY;
@@ -52,6 +53,7 @@ import static androidx.media3.test.session.common.MediaBrowserConstants.SEARCH_Q
 import static androidx.media3.test.session.common.MediaBrowserConstants.SEARCH_QUERY_LONG_LIST;
 import static androidx.media3.test.session.common.MediaBrowserConstants.SEARCH_RESULT;
 import static androidx.media3.test.session.common.MediaBrowserConstants.SEARCH_RESULT_COUNT;
+import static androidx.media3.test.session.common.MediaBrowserConstants.SUBSCRIBE_PARENT_ID_2;
 import static androidx.media3.test.session.common.TestUtils.LONG_TIMEOUT_MS;
 import static androidx.media3.test.session.common.TestUtils.NO_RESPONSE_TIMEOUT_MS;
 import static androidx.media3.test.session.common.TestUtils.SERVICE_CONNECTION_TIMEOUT_MS;
@@ -481,6 +483,70 @@ public class MediaBrowserCompatWithMediaLibraryServiceTest
     assertThat(onChildrenLoadedWithBundleCalled.get()).isFalse();
   }
 
+  @Test
+  public void getChildren_browserNotifyChildrenChanged_callsOnChildrenLoadedTwice()
+      throws Exception {
+    String testParentId = SUBSCRIBE_PARENT_ID_2;
+    connectAndWait(/* rootHints= */ Bundle.EMPTY);
+    CountDownLatch latch = new CountDownLatch(2);
+    List<String> parentIds = new ArrayList<>();
+    List<List<MediaItem>> childrenList = new ArrayList<>();
+    Bundle requestNotifyChildrenWithDelayBundle =
+        createNotifyChildrenChangedBundle(
+            testParentId, /* itemCount= */ 12, /* delayMs= */ 100L, /* broadcast= */ false);
+    requestNotifyChildrenWithDelayBundle.putInt(MediaBrowserCompat.EXTRA_PAGE_SIZE, 12);
+
+    browserCompat.subscribe(
+        testParentId,
+        requestNotifyChildrenWithDelayBundle,
+        new SubscriptionCallback() {
+          @Override
+          public void onChildrenLoaded(String parentId, List<MediaItem> children, Bundle options) {
+            parentIds.add(parentId);
+            childrenList.add(children);
+            latch.countDown();
+          }
+        });
+
+    assertThat(latch.await(TIMEOUT_MS, MILLISECONDS)).isTrue();
+    assertThat(parentIds).containsExactly(testParentId, testParentId);
+    assertThat(childrenList).hasSize(2);
+    assertThat(childrenList.get(0)).hasSize(12);
+    assertThat(childrenList.get(1)).hasSize(12);
+  }
+
+  @Test
+  public void getChildren_broadcastNotifyChildrenChanged_callsOnChildrenLoadedTwice()
+      throws Exception {
+    String testParentId = SUBSCRIBE_PARENT_ID_2;
+    connectAndWait(/* rootHints= */ Bundle.EMPTY);
+    CountDownLatch latch = new CountDownLatch(2);
+    List<String> parentIds = new ArrayList<>();
+    List<List<MediaItem>> childrenList = new ArrayList<>();
+    Bundle requestNotifyChildrenWithDelayBundle =
+        createNotifyChildrenChangedBundle(
+            testParentId, /* itemCount= */ 12, /* delayMs= */ 100L, /* broadcast= */ true);
+    requestNotifyChildrenWithDelayBundle.putInt(MediaBrowserCompat.EXTRA_PAGE_SIZE, 12);
+
+    browserCompat.subscribe(
+        testParentId,
+        requestNotifyChildrenWithDelayBundle,
+        new SubscriptionCallback() {
+          @Override
+          public void onChildrenLoaded(String parentId, List<MediaItem> children, Bundle options) {
+            parentIds.add(parentId);
+            childrenList.add(children);
+            latch.countDown();
+          }
+        });
+
+    assertThat(latch.await(TIMEOUT_MS, MILLISECONDS)).isTrue();
+    assertThat(parentIds).containsExactly(testParentId, testParentId);
+    assertThat(childrenList).hasSize(2);
+    assertThat(childrenList.get(0)).hasSize(12);
+    assertThat(childrenList.get(1)).hasSize(12);
+  }
+
   @Test
   public void getChildren_commandGetChildrenNotAvailable_reportsError() throws Exception {
     Bundle rootHints = new Bundle();
diff --git a/libraries/test_session_current/src/main/java/androidx/media3/session/MockMediaLibraryService.java b/libraries/test_session_current/src/main/java/androidx/media3/session/MockMediaLibraryService.java
index 7aa60a333e..1f90c68609 100644
--- a/libraries/test_session_current/src/main/java/androidx/media3/session/MockMediaLibraryService.java
+++ b/libraries/test_session_current/src/main/java/androidx/media3/session/MockMediaLibraryService.java
@@ -337,7 +337,8 @@ public class MockMediaLibraryService extends MediaLibraryService {
       assertLibraryParams(params);
       if (Objects.equals(parentId, PARENT_ID_NO_CHILDREN)) {
         return Futures.immediateFuture(LibraryResult.ofItemList(ImmutableList.of(), params));
-      } else if (Objects.equals(parentId, PARENT_ID)) {
+      } else if (Objects.equals(parentId, PARENT_ID)
+          || Objects.equals(parentId, SUBSCRIBE_PARENT_ID_2)) {
         return Futures.immediateFuture(
             LibraryResult.ofItemList(
                 getPaginatedResult(GET_CHILDREN_RESULT, page, pageSize), params));