diff --git a/app/k9mail-jmap/src/main/java/com/fsck/k9/ui/addaccount/AddAccountActivity.kt b/app/k9mail-jmap/src/main/java/com/fsck/k9/ui/addaccount/AddAccountActivity.kt
index 21225ff99..bade75d0f 100644
--- a/app/k9mail-jmap/src/main/java/com/fsck/k9/ui/addaccount/AddAccountActivity.kt
+++ b/app/k9mail-jmap/src/main/java/com/fsck/k9/ui/addaccount/AddAccountActivity.kt
@@ -6,7 +6,7 @@ import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.setupActionBarWithNavController
 import com.fsck.k9.jmap.R
 import com.fsck.k9.ui.base.K9Activity
-import com.fsck.k9.ui.findNavController
+import com.fsck.k9.ui.base.extensions.findNavController
 
 class AddAccountActivity : K9Activity() {
     private lateinit var navController: NavController
diff --git a/app/ui/base/build.gradle b/app/ui/base/build.gradle
index 5827ad705..3451facf9 100644
--- a/app/ui/base/build.gradle
+++ b/app/ui/base/build.gradle
@@ -8,6 +8,8 @@ dependencies {
     implementation project(":app:core")
 
     api "androidx.appcompat:appcompat:${versions.androidxAppCompat}"
+    api "androidx.navigation:navigation-fragment-ktx:${versions.androidxNavigation}"
+    api "androidx.navigation:navigation-ui-ktx:${versions.androidxNavigation}"
 
     implementation "androidx.core:core-ktx:${versions.androidxCore}"
     implementation "com.jakewharton.timber:timber:${versions.timber}"
diff --git a/app/ui/legacy/src/main/java/com/fsck/k9/ui/NavigationExtensions.kt b/app/ui/base/src/main/java/com/fsck/k9/ui/base/extensions/NavigationExtensions.kt
similarity index 91%
rename from app/ui/legacy/src/main/java/com/fsck/k9/ui/NavigationExtensions.kt
rename to app/ui/base/src/main/java/com/fsck/k9/ui/base/extensions/NavigationExtensions.kt
index 740cc2c9a..ec72096de 100644
--- a/app/ui/legacy/src/main/java/com/fsck/k9/ui/NavigationExtensions.kt
+++ b/app/ui/base/src/main/java/com/fsck/k9/ui/base/extensions/NavigationExtensions.kt
@@ -1,4 +1,4 @@
-package com.fsck.k9.ui
+package com.fsck.k9.ui.base.extensions
 
 import androidx.annotation.IdRes
 import androidx.fragment.app.FragmentActivity
diff --git a/app/ui/legacy/build.gradle b/app/ui/legacy/build.gradle
index dba9529b1..d1360b095 100644
--- a/app/ui/legacy/build.gradle
+++ b/app/ui/legacy/build.gradle
@@ -27,8 +27,6 @@ dependencies {
     implementation "androidx.recyclerview:recyclerview:${versions.androidxRecyclerView}"
     implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:${versions.androidxLifecycle}"
     implementation "androidx.lifecycle:lifecycle-livedata-ktx:${versions.androidxLifecycle}"
-    implementation "androidx.navigation:navigation-fragment-ktx:${versions.androidxNavigation}"
-    implementation "androidx.navigation:navigation-ui-ktx:${versions.androidxNavigation}"
     implementation "androidx.constraintlayout:constraintlayout:${versions.androidxConstraintLayout}"
     implementation "androidx.cardview:cardview:${versions.androidxCardView}"
     implementation "androidx.localbroadcastmanager:localbroadcastmanager:1.0.0"
diff --git a/app/ui/legacy/src/main/java/com/fsck/k9/ui/managefolders/ManageFoldersActivity.kt b/app/ui/legacy/src/main/java/com/fsck/k9/ui/managefolders/ManageFoldersActivity.kt
index 41cc4ffcd..e648938b9 100644
--- a/app/ui/legacy/src/main/java/com/fsck/k9/ui/managefolders/ManageFoldersActivity.kt
+++ b/app/ui/legacy/src/main/java/com/fsck/k9/ui/managefolders/ManageFoldersActivity.kt
@@ -10,7 +10,7 @@ import androidx.navigation.ui.setupActionBarWithNavController
 import com.fsck.k9.Account
 import com.fsck.k9.ui.R
 import com.fsck.k9.ui.base.K9Activity
-import com.fsck.k9.ui.findNavController
+import com.fsck.k9.ui.base.extensions.findNavController
 
 class ManageFoldersActivity : K9Activity() {
     private lateinit var navController: NavController
diff --git a/app/ui/legacy/src/main/java/com/fsck/k9/ui/onboarding/OnboardingActivity.kt b/app/ui/legacy/src/main/java/com/fsck/k9/ui/onboarding/OnboardingActivity.kt
index b8fe8202d..b1919fed9 100644
--- a/app/ui/legacy/src/main/java/com/fsck/k9/ui/onboarding/OnboardingActivity.kt
+++ b/app/ui/legacy/src/main/java/com/fsck/k9/ui/onboarding/OnboardingActivity.kt
@@ -8,7 +8,7 @@ import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.setupActionBarWithNavController
 import com.fsck.k9.ui.R
 import com.fsck.k9.ui.base.K9Activity
-import com.fsck.k9.ui.findNavController
+import com.fsck.k9.ui.base.extensions.findNavController
 
 class OnboardingActivity : K9Activity() {
     private lateinit var navController: NavController
diff --git a/app/ui/legacy/src/main/java/com/fsck/k9/ui/settings/SettingsActivity.kt b/app/ui/legacy/src/main/java/com/fsck/k9/ui/settings/SettingsActivity.kt
index 74bbd4b7f..1fc0e6474 100644
--- a/app/ui/legacy/src/main/java/com/fsck/k9/ui/settings/SettingsActivity.kt
+++ b/app/ui/legacy/src/main/java/com/fsck/k9/ui/settings/SettingsActivity.kt
@@ -8,7 +8,7 @@ import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.setupActionBarWithNavController
 import com.fsck.k9.ui.R
 import com.fsck.k9.ui.base.K9Activity
-import com.fsck.k9.ui.findNavController
+import com.fsck.k9.ui.base.extensions.findNavController
 
 class SettingsActivity : K9Activity() {
     private lateinit var navController: NavController