diff --git a/lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/bottomtabs/BottomTabsController.java b/lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/bottomtabs/BottomTabsController.java
index 2b44a620382..0907a6a3c8a 100644
--- a/lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/bottomtabs/BottomTabsController.java
+++ b/lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/bottomtabs/BottomTabsController.java
@@ -159,7 +159,7 @@ public void sendOnNavigationButtonPressed(String buttonId) {
     }
 
     @Override
-    public ViewController getCurrentChild() {
+    public ViewController<?> getCurrentChild() {
         return tabs.get(bottomTabs == null ? 0 : bottomTabs.getCurrentItem());
     }
 
diff --git a/lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/stack/StackController.java b/lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/stack/StackController.java
index 93a3744ffcb..d338294f3f0 100644
--- a/lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/stack/StackController.java
+++ b/lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/stack/StackController.java
@@ -62,6 +62,9 @@ public StackController(Activity activity, List<ViewController> children, ChildCo
         this.fabPresenter = fabPresenter;
         stackPresenter.setButtonOnClickListener(this::onNavigationButtonPressed);
         for (ViewController child : children) {
+            if (stack.containsId(child.getId())) {
+                throw new IllegalArgumentException("A stack can't contain two children with the same id: " + child.getId());
+            }
             child.setParentController(this);
             stack.push(child.getId(), child);
             if (size() > 1) backButtonHelper.addToPushedChild(child);
@@ -86,7 +89,7 @@ public void setDefaultOptions(Options defaultOptions) {
     }
 
     @Override
-    public ViewController getCurrentChild() {
+    public ViewController<?> getCurrentChild() {
         return stack.peek();
     }
 
@@ -151,7 +154,7 @@ public void onChildDestroyed(ViewController child) {
 
     public void push(ViewController child, CommandListener listener) {
         if (findController(child.getId()) != null) {
-            listener.onError("A stack can't contain two children with the same id");
+            listener.onError("A stack can't contain two children with the same id: " + child.getId());
             return;
         }
         final ViewController toRemove = stack.peek();
@@ -240,7 +243,7 @@ public void onSuccess(String childId) {
                         resolvedOptions,
                         presenter.getAdditionalSetRootAnimations(this, child, resolvedOptions),
                         () -> listenerAdapter.onSuccess(child.getId())
-                    )
+                        )
                 );
             } else {
                 animator.setRoot(child,
diff --git a/lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/stack/StackControllerTest.kt b/lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/stack/StackControllerTest.kt
index cb2601bbd63..403abec0004 100644
--- a/lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/stack/StackControllerTest.kt
+++ b/lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/stack/StackControllerTest.kt
@@ -36,10 +36,9 @@ import org.json.JSONObject
 import org.junit.Ignore
 import org.junit.Test
 import org.robolectric.Robolectric
-import org.robolectric.annotation.LooperMode
 import org.robolectric.shadows.ShadowLooper
 import java.util.*
-import kotlin.jvm.Throws
+import kotlin.test.fail
 
 class StackControllerTest : BaseTest() {
     private lateinit var activity: Activity
@@ -99,6 +98,16 @@ class StackControllerTest : BaseTest() {
         assertThat(uut).isInstanceOf(ViewController::class.java)
     }
 
+    @Test
+    fun childrenMustBeUniqueById() {
+        try {
+            val uut: StackController = createStack(listOf(child1, child2, child1))
+            fail("Stack should not have duplicate ids!")
+        } catch (e: IllegalArgumentException) {
+            assertThat(e.message).contains(child1.id)
+        }
+    }
+
     @Test
     fun childrenAreAssignedParent() {
         val uut: StackController = createStack(listOf(child1, child2))