diff --git a/app/src/main/java/de/grobox/transportr/settings/SettingsFragment.kt b/app/src/main/java/de/grobox/transportr/settings/SettingsFragment.kt
index f72f78c73..57a0cc0ff 100644
--- a/app/src/main/java/de/grobox/transportr/settings/SettingsFragment.kt
+++ b/app/src/main/java/de/grobox/transportr/settings/SettingsFragment.kt
@@ -60,9 +60,9 @@ class SettingsFragment : PreferenceFragmentCompat() {
 
         // Fill in current transport network if available
         networkPref = findPreference("pref_key_network")!!
-        manager.transportNetwork.observe(this, Observer<TransportNetwork> {
+        manager.transportNetwork.observe(this) {
             onTransportNetworkChanged(it)
-        })
+        }
 
         networkPref.setOnPreferenceClickListener {
             if (activity == null || view == null) return@setOnPreferenceClickListener false
diff --git a/app/src/main/java/de/grobox/transportr/settings/SettingsManager.kt b/app/src/main/java/de/grobox/transportr/settings/SettingsManager.kt
index c1f9cc628..521a509d6 100644
--- a/app/src/main/java/de/grobox/transportr/settings/SettingsManager.kt
+++ b/app/src/main/java/de/grobox/transportr/settings/SettingsManager.kt
@@ -24,8 +24,10 @@ import android.content.SharedPreferences
 import android.content.res.Configuration
 import android.content.res.Resources
 import android.os.Build
+import android.os.PowerManager
 import android.preference.PreferenceManager
 import androidx.appcompat.app.AppCompatDelegate.*
+import androidx.core.content.ContextCompat
 import de.grobox.transportr.R
 import de.schildbach.pte.NetworkId
 import de.schildbach.pte.NetworkProvider.Optimize
@@ -67,8 +69,14 @@ class SettingsManager @Inject constructor(private val context: Context) {
 
     val isDarkTheme: Boolean
         get() {
-            return (context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK == Configuration.UI_MODE_NIGHT_YES) or
-                    (theme == MODE_NIGHT_YES)
+            return when(theme) {
+                MODE_NIGHT_YES -> true
+                MODE_NIGHT_NO -> false
+                else -> if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q)
+                    context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK == Configuration.UI_MODE_NIGHT_YES
+                else
+                    ContextCompat.getSystemService(context, PowerManager::class.java)?.isPowerSaveMode ?: false
+            }
         }
 
     val walkSpeed: WalkSpeed
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
index 8dfa735f1..172952f0e 100644
--- a/app/src/main/res/xml/preferences.xml
+++ b/app/src/main/res/xml/preferences.xml
@@ -49,7 +49,7 @@
 		app:iconSpaceReserved="false">
 
 		<ListPreference
-			android:defaultValue="@string/pref_theme_value_light"
+			android:defaultValue="@string/pref_theme_value_auto"
 			android:entries="@array/pref_theme_options"
 			android:entryValues="@array/pref_theme_values"
 			android:key="pref_key_theme"