diff --git a/app/src/main/kotlin/dev/meloda/fast/model/BottomNavigationItem.kt b/app/src/main/kotlin/dev/meloda/fast/model/BottomNavigationItem.kt
index 01be1997..5345d94c 100644
--- a/app/src/main/kotlin/dev/meloda/fast/model/BottomNavigationItem.kt
+++ b/app/src/main/kotlin/dev/meloda/fast/model/BottomNavigationItem.kt
@@ -1,5 +1,8 @@
 package dev.meloda.fast.model
 
+import androidx.compose.runtime.Immutable
+
+@Immutable
 data class BottomNavigationItem(
     val titleResId: Int,
     val selectedIconResId: Int,
diff --git a/app/src/main/kotlin/dev/meloda/fast/navigation/MainGraph.kt b/app/src/main/kotlin/dev/meloda/fast/navigation/MainGraph.kt
index dea46be2..6c6e39db 100644
--- a/app/src/main/kotlin/dev/meloda/fast/navigation/MainGraph.kt
+++ b/app/src/main/kotlin/dev/meloda/fast/navigation/MainGraph.kt
@@ -8,6 +8,7 @@ import dev.meloda.fast.model.BaseError
 import dev.meloda.fast.model.BottomNavigationItem
 import dev.meloda.fast.presentation.MainScreen
 import dev.meloda.fast.profile.navigation.Profile
+import dev.meloda.fast.ui.util.ImmutableList
 import kotlinx.serialization.Serializable
 import dev.meloda.fast.ui.R as UiR
 
@@ -23,7 +24,7 @@ fun NavGraphBuilder.mainScreen(
     onConversationClicked: (conversationId: Int) -> Unit,
     onPhotoClicked: (url: String) -> Unit
 ) {
-    val navigationItems = listOf(
+    val navigationItems = ImmutableList.of(
         BottomNavigationItem(
             titleResId = UiR.string.title_friends,
             selectedIconResId = UiR.drawable.baseline_people_alt_24,
diff --git a/app/src/main/kotlin/dev/meloda/fast/presentation/MainScreen.kt b/app/src/main/kotlin/dev/meloda/fast/presentation/MainScreen.kt
index 8de90ec5..5bd64261 100644
--- a/app/src/main/kotlin/dev/meloda/fast/presentation/MainScreen.kt
+++ b/app/src/main/kotlin/dev/meloda/fast/presentation/MainScreen.kt
@@ -38,11 +38,12 @@ import dev.meloda.fast.profile.navigation.profileScreen
 import dev.meloda.fast.ui.theme.LocalBottomPadding
 import dev.meloda.fast.ui.theme.LocalHazeState
 import dev.meloda.fast.ui.theme.LocalThemeConfig
+import dev.meloda.fast.ui.util.ImmutableList
 
 @OptIn(ExperimentalHazeMaterialsApi::class)
 @Composable
 fun MainScreen(
-    navigationItems: List<BottomNavigationItem>,
+    navigationItems: ImmutableList<BottomNavigationItem>,
     onError: (BaseError) -> Unit = {},
     onSettingsButtonClicked: () -> Unit = {},
     onConversationItemClicked: (conversationId: Int) -> Unit = {},
diff --git a/app/src/main/kotlin/dev/meloda/fast/presentation/RootScreen.kt b/app/src/main/kotlin/dev/meloda/fast/presentation/RootScreen.kt
index 27dc82c9..c64f7f3b 100644
--- a/app/src/main/kotlin/dev/meloda/fast/presentation/RootScreen.kt
+++ b/app/src/main/kotlin/dev/meloda/fast/presentation/RootScreen.kt
@@ -21,7 +21,6 @@ import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.rememberNavController
 import dev.meloda.fast.MainViewModel
-import dev.meloda.fast.MainViewModelImpl
 import dev.meloda.fast.auth.authNavGraph
 import dev.meloda.fast.auth.navigateToAuth
 import dev.meloda.fast.chatmaterials.navigation.chatMaterialsScreen
@@ -37,12 +36,11 @@ import dev.meloda.fast.photoviewer.navigation.photoViewScreen
 import dev.meloda.fast.settings.navigation.navigateToSettings
 import dev.meloda.fast.settings.navigation.settingsScreen
 import dev.meloda.fast.ui.R
-import org.koin.androidx.compose.koinViewModel
 
 @Composable
 fun RootScreen(
     navController: NavHostController = rememberNavController(),
-    viewModel: MainViewModel = koinViewModel<MainViewModelImpl>()
+    viewModel: MainViewModel
 ) {
     val context = LocalContext.current
     val startDestination by viewModel.startDestination.collectAsStateWithLifecycle()
diff --git a/core/ui/src/main/kotlin/dev/meloda/fast/ui/util/ImmutableList.kt b/core/ui/src/main/kotlin/dev/meloda/fast/ui/util/ImmutableList.kt
index 12a7b1c5..a9a2b631 100644
--- a/core/ui/src/main/kotlin/dev/meloda/fast/ui/util/ImmutableList.kt
+++ b/core/ui/src/main/kotlin/dev/meloda/fast/ui/util/ImmutableList.kt
@@ -7,10 +7,7 @@ class ImmutableList<T>(val values: List<T>) : Iterable<T> {
 
     constructor(size: Int, init: (index: Int) -> T) : this(MutableList(size, init))
 
-    operator fun get(index: Int): T? {
-        values.singleOrNull()
-        return values[index]
-    }
+    operator fun get(index: Int): T = values[index]
 
     inline fun forEach(action: (T) -> Unit) {
         for (element in values) action(element)
diff --git a/feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/di/ConversationsModule.kt b/feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/di/ConversationsModule.kt
index 9110c57f..5fca2061 100644
--- a/feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/di/ConversationsModule.kt
+++ b/feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/di/ConversationsModule.kt
@@ -10,6 +10,5 @@ import org.koin.dsl.module
 
 val conversationsModule = module {
     singleOf(::ConversationsUseCaseImpl) bind ConversationsUseCase::class
-
     viewModelOf(::ConversationsViewModelImpl)
 }
diff --git a/feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/presentation/ConversationsScreen.kt b/feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/presentation/ConversationsScreen.kt
index 58fc683b..5f4590bb 100644
--- a/feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/presentation/ConversationsScreen.kt
+++ b/feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/presentation/ConversationsScreen.kt
@@ -71,7 +71,6 @@ import dev.chrisbanes.haze.hazeChild
 import dev.chrisbanes.haze.materials.ExperimentalHazeMaterialsApi
 import dev.chrisbanes.haze.materials.HazeMaterials
 import dev.meloda.fast.conversations.ConversationsViewModel
-import dev.meloda.fast.conversations.ConversationsViewModelImpl
 import dev.meloda.fast.conversations.model.ConversationOption
 import dev.meloda.fast.conversations.model.ConversationsScreenState
 import dev.meloda.fast.conversations.model.UiConversation
@@ -85,7 +84,6 @@ import dev.meloda.fast.ui.theme.LocalHazeState
 import dev.meloda.fast.ui.theme.LocalThemeConfig
 import dev.meloda.fast.ui.util.isScrollingUp
 import kotlinx.coroutines.launch
-import org.koin.androidx.compose.koinViewModel
 import org.koin.compose.koinInject
 import dev.meloda.fast.ui.R as UiR
 
@@ -94,7 +92,7 @@ fun ConversationsRoute(
     onError: (BaseError) -> Unit,
     onConversationItemClicked: (conversationId: Int) -> Unit,
     onPhotoClicked: (url: String) -> Unit,
-    viewModel: ConversationsViewModel = koinViewModel<ConversationsViewModelImpl>()
+    viewModel: ConversationsViewModel
 ) {
     val context = LocalContext.current