diff --git a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
index 89f4890c254ed..3b45d5d88d122 100644
--- a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
+++ b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java
@@ -1418,7 +1418,7 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
         if (splitRule instanceof SplitPairRule && ((SplitPairRule) splitRule).shouldClearTop()) {
             removeExistingSecondaryContainers(wct, primaryContainer);
         }
-        primaryContainer.getTaskContainer().mSplitContainers.add(splitContainer);
+        primaryContainer.getTaskContainer().addSplitContainer(splitContainer);
     }
 
     /** Cleanups all the dependencies when the TaskFragment is entering PIP. */
@@ -1430,8 +1430,9 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
             return;
         }
         final List<SplitContainer> splitsToRemove = new ArrayList<>();
+        final List<SplitContainer> splitContainers = taskContainer.getSplitContainers();
         final Set<TaskFragmentContainer> containersToUpdate = new ArraySet<>();
-        for (SplitContainer splitContainer : taskContainer.mSplitContainers) {
+        for (SplitContainer splitContainer : splitContainers) {
             if (splitContainer.getPrimaryContainer() != container
                     && splitContainer.getSecondaryContainer() != container) {
                 continue;
@@ -1449,7 +1450,7 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
             }
         }
         container.resetDependencies();
-        taskContainer.mSplitContainers.removeAll(splitsToRemove);
+        taskContainer.removeSplitContainers(splitsToRemove);
         // If there is any TaskFragment split with the PIP TaskFragment, update their presentations
         // since the split is dismissed.
         // We don't want to close any of them even if they are dependencies of the PIP TaskFragment.
@@ -1481,7 +1482,8 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
 
         // Cleanup any split references.
         final List<SplitContainer> containersToRemove = new ArrayList<>();
-        for (SplitContainer splitContainer : taskContainer.mSplitContainers) {
+        final List<SplitContainer> splitContainers = taskContainer.getSplitContainers();
+        for (SplitContainer splitContainer : splitContainers) {
             if (containersToRemove.contains(splitContainer)) {
                 // Don't need to check because it has been in the remove list.
                 continue;
@@ -1492,7 +1494,7 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
                 containersToRemove.add(splitContainer);
             }
         }
-        taskContainer.mSplitContainers.removeAll(containersToRemove);
+        taskContainer.removeSplitContainers(containersToRemove);
 
         // Cleanup any dependent references.
         for (TaskFragmentContainer containerToUpdate : taskContainer.mContainers) {
@@ -1629,7 +1631,7 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
     /** Whether the given split is the topmost split in the Task. */
     private boolean isTopMostSplit(@NonNull SplitContainer splitContainer) {
         final List<SplitContainer> splitContainers = splitContainer.getPrimaryContainer()
-                .getTaskContainer().mSplitContainers;
+                .getTaskContainer().getSplitContainers();
         return splitContainer == splitContainers.get(splitContainers.size() - 1);
     }
 
@@ -1641,7 +1643,8 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
         if (container == null) {
             return null;
         }
-        final List<SplitContainer> splitContainers = container.getTaskContainer().mSplitContainers;
+        final List<SplitContainer> splitContainers =
+                container.getTaskContainer().getSplitContainers();
         if (splitContainers.isEmpty()) {
             return null;
         }
@@ -1665,7 +1668,7 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
             @NonNull TaskFragmentContainer firstContainer,
             @NonNull TaskFragmentContainer secondContainer) {
         final List<SplitContainer> splitContainers = firstContainer.getTaskContainer()
-                .mSplitContainers;
+                .getSplitContainers();
         for (int i = splitContainers.size() - 1; i >= 0; i--) {
             final SplitContainer splitContainer = splitContainers.get(i);
             final TaskFragmentContainer primary = splitContainer.getPrimaryContainer();
@@ -1945,7 +1948,7 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
     @GuardedBy("mLock")
     SplitContainer getSplitContainer(@NonNull IBinder token) {
         for (int i = mTaskContainers.size() - 1; i >= 0; i--) {
-            final List<SplitContainer> containers = mTaskContainers.valueAt(i).mSplitContainers;
+            final List<SplitContainer> containers = mTaskContainers.valueAt(i).getSplitContainers();
             for (SplitContainer container : containers) {
                 if (container.getToken().equals(token)) {
                     return container;
diff --git a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskContainer.java b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskContainer.java
index 4b15bb187035e..06265105028b9 100644
--- a/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskContainer.java
+++ b/libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskContainer.java
@@ -55,7 +55,7 @@ class TaskContainer {
 
     /** Active split pairs in this Task. */
     @NonNull
-    final List<SplitContainer> mSplitContainers = new ArrayList<>();
+    private final List<SplitContainer> mSplitContainers = new ArrayList<>();
 
     @NonNull
     private final Configuration mConfiguration;
@@ -207,6 +207,19 @@ class TaskContainer {
         return false;
     }
 
+    @NonNull
+    List<SplitContainer> getSplitContainers() {
+        return new ArrayList<>(mSplitContainers);
+    }
+
+    void addSplitContainer(@NonNull SplitContainer splitContainer) {
+        mSplitContainers.add(splitContainer);
+    }
+
+    void removeSplitContainers(@NonNull List<SplitContainer> containers) {
+        mSplitContainers.removeAll(containers);
+    }
+
     /** Adds the descriptors of split states in this Task to {@code outSplitStates}. */
     void getSplitStates(@NonNull List<SplitInfo> outSplitStates) {
         for (SplitContainer container : mSplitContainers) {
diff --git a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/SplitControllerTest.java b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/SplitControllerTest.java
index ff08782e8cd8d..82692a5170df4 100644
--- a/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/SplitControllerTest.java
+++ b/libs/WindowManager/Jetpack/tests/unittest/src/androidx/window/extensions/embedding/SplitControllerTest.java
@@ -320,11 +320,11 @@ public class SplitControllerTest {
         doReturn(tf).when(splitContainer).getSecondaryContainer();
         doReturn(createTestTaskContainer()).when(splitContainer).getTaskContainer();
         doReturn(createSplitRule(mActivity, mActivity)).when(splitContainer).getSplitRule();
-        final List<SplitContainer> splitContainers =
-                mSplitController.getTaskContainer(TASK_ID).mSplitContainers;
-        splitContainers.add(splitContainer);
+        final TaskContainer taskContainer = mSplitController.getTaskContainer(TASK_ID);
+        taskContainer.addSplitContainer(splitContainer);
         // Add a mock SplitContainer on top of splitContainer
-        splitContainers.add(1, mock(SplitContainer.class));
+        final SplitContainer splitContainer2 = mock(SplitContainer.class);
+        taskContainer.addSplitContainer(splitContainer2);
 
         mSplitController.updateContainer(mTransaction, tf);
 
@@ -332,7 +332,9 @@ public class SplitControllerTest {
 
         // Verify if one or both containers in the top SplitContainer are finished,
         // dismissPlaceholder() won't be called.
-        splitContainers.remove(1);
+        final ArrayList<SplitContainer> splitContainersToRemove = new ArrayList<>();
+        splitContainersToRemove.add(splitContainer2);
+        taskContainer.removeSplitContainers(splitContainersToRemove);
         doReturn(true).when(tf).isFinished();
 
         mSplitController.updateContainer(mTransaction, tf);
@@ -377,7 +379,7 @@ public class SplitControllerTest {
         doReturn(true).when(taskContainer).isVisible();
         mSplitController.updateContainer(mTransaction, taskFragmentContainer);
 
-        verify(mSplitPresenter).updateSplitContainer(taskContainer.mSplitContainers.get(0),
+        verify(mSplitPresenter).updateSplitContainer(taskContainer.getSplitContainers().get(0),
                 mTransaction);
     }
 
@@ -1091,7 +1093,7 @@ public class SplitControllerTest {
         verify(mTransaction).finishActivity(secondaryActivity0.getActivityToken());
         verify(mTransaction).finishActivity(secondaryActivity1.getActivityToken());
         assertTrue(taskContainer.mContainers.isEmpty());
-        assertTrue(taskContainer.mSplitContainers.isEmpty());
+        assertTrue(taskContainer.getSplitContainers().isEmpty());
     }
 
     @Test