diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupCreateService.kt b/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupCreateService.kt
index a212db9de4..8b000f0cf0 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupCreateService.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupCreateService.kt
@@ -9,6 +9,7 @@ import android.os.IBinder
 import android.os.PowerManager
 import com.hippo.unifile.UniFile
 import eu.kanade.tachiyomi.data.notification.Notifications
+import eu.kanade.tachiyomi.util.system.acquireWakeLock
 import eu.kanade.tachiyomi.util.system.isServiceRunning
 
 /**
@@ -73,10 +74,7 @@ class BackupCreateService : Service() {
 
         startForeground(Notifications.ID_BACKUP_PROGRESS, notifier.showBackupProgress().build())
 
-        wakeLock = (getSystemService(Context.POWER_SERVICE) as PowerManager).newWakeLock(
-            PowerManager.PARTIAL_WAKE_LOCK, "${javaClass.name}:WakeLock"
-        )
-        wakeLock.acquire()
+        wakeLock = acquireWakeLock(javaClass.name)
     }
 
     override fun stopService(name: Intent?): Boolean {
diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupManager.kt b/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupManager.kt
index f90a91832d..f2aa054c36 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupManager.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupManager.kt
@@ -46,6 +46,7 @@ import eu.kanade.tachiyomi.data.database.models.Track
 import eu.kanade.tachiyomi.data.database.models.TrackImpl
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import eu.kanade.tachiyomi.data.track.TrackManager
+import eu.kanade.tachiyomi.source.LocalSource
 import eu.kanade.tachiyomi.source.Source
 import eu.kanade.tachiyomi.source.SourceManager
 import eu.kanade.tachiyomi.util.chapter.syncChaptersWithSource
@@ -131,8 +132,10 @@ class BackupManager(val context: Context, version: Int = CURRENT_VERSION) {
                 mangaEntries.add(backupMangaObject(manga, flags))
 
                 // Maintain set of extensions/sources used (excludes local source)
-                if (manga.source != 0L && sourceManager.get(manga.source) != null) {
-                    extensions.add("${manga.source}:${sourceManager.get(manga.source)!!.name}")
+                if (manga.source != LocalSource.ID) {
+                    sourceManager.get(manga.source)?.let {
+                        extensions.add("${manga.source}:${it.name}")
+                    }
                 }
             }
 
diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestoreService.kt b/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestoreService.kt
index ed2aba4dd3..e5adbcfbb5 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestoreService.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestoreService.kt
@@ -32,6 +32,7 @@ import eu.kanade.tachiyomi.data.database.models.TrackImpl
 import eu.kanade.tachiyomi.data.notification.Notifications
 import eu.kanade.tachiyomi.data.track.TrackManager
 import eu.kanade.tachiyomi.source.Source
+import eu.kanade.tachiyomi.util.system.acquireWakeLock
 import eu.kanade.tachiyomi.util.system.isServiceRunning
 import java.io.File
 import java.text.SimpleDateFormat
@@ -127,10 +128,7 @@ class BackupRestoreService : Service() {
 
         startForeground(Notifications.ID_RESTORE_PROGRESS, notifier.showRestoreProgress().build())
 
-        wakeLock = (getSystemService(Context.POWER_SERVICE) as PowerManager).newWakeLock(
-            PowerManager.PARTIAL_WAKE_LOCK, "${javaClass.name}:WakeLock"
-        )
-        wakeLock.acquire()
+        wakeLock = acquireWakeLock(javaClass.name)
     }
 
     override fun stopService(name: Intent?): Boolean {
diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadService.kt b/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadService.kt
index 332ac1ea8e..6b3dda2995 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadService.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadService.kt
@@ -16,9 +16,9 @@ import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.notification.Notifications
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import eu.kanade.tachiyomi.util.lang.plusAssign
+import eu.kanade.tachiyomi.util.system.acquireWakeLock
 import eu.kanade.tachiyomi.util.system.connectivityManager
 import eu.kanade.tachiyomi.util.system.notification
-import eu.kanade.tachiyomi.util.system.powerManager
 import eu.kanade.tachiyomi.util.system.toast
 import rx.android.schedulers.AndroidSchedulers
 import rx.schedulers.Schedulers
@@ -70,9 +70,7 @@ class DownloadService : Service() {
     /**
      * Wake lock to prevent the device to enter sleep mode.
      */
-    private val wakeLock by lazy {
-        powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "DownloadService:WakeLock")
-    }
+    private lateinit var wakeLock: PowerManager.WakeLock
 
     /**
      * Subscriptions to store while the service is running.
@@ -85,6 +83,7 @@ class DownloadService : Service() {
     override fun onCreate() {
         super.onCreate()
         startForeground(Notifications.ID_DOWNLOAD_CHAPTER, getPlaceholderNotification())
+        wakeLock = acquireWakeLock(javaClass.name)
         runningRelay.call(true)
         subscriptions = CompositeSubscription()
         listenDownloaderState()
diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateService.kt b/app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateService.kt
index 5d33d56db3..39f36b4045 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateService.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateService.kt
@@ -35,6 +35,7 @@ import eu.kanade.tachiyomi.source.online.HttpSource
 import eu.kanade.tachiyomi.ui.main.MainActivity
 import eu.kanade.tachiyomi.util.chapter.syncChaptersWithSource
 import eu.kanade.tachiyomi.util.lang.chop
+import eu.kanade.tachiyomi.util.system.acquireWakeLock
 import eu.kanade.tachiyomi.util.system.isServiceRunning
 import eu.kanade.tachiyomi.util.system.notification
 import eu.kanade.tachiyomi.util.system.notificationBuilder
@@ -182,11 +183,10 @@ class LibraryUpdateService(
      */
     override fun onCreate() {
         super.onCreate()
+
         startForeground(Notifications.ID_LIBRARY_PROGRESS, progressNotificationBuilder.build())
-        wakeLock = (getSystemService(Context.POWER_SERVICE) as PowerManager).newWakeLock(
-            PowerManager.PARTIAL_WAKE_LOCK, "LibraryUpdateService:WakeLock"
-        )
-        wakeLock.acquire()
+
+        wakeLock = acquireWakeLock(javaClass.name)
     }
 
     /**
diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/updater/UpdaterService.kt b/app/src/main/java/eu/kanade/tachiyomi/data/updater/UpdaterService.kt
index 4cfec811bc..23e0154388 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/updater/UpdaterService.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/updater/UpdaterService.kt
@@ -18,6 +18,7 @@ import eu.kanade.tachiyomi.network.newCallWithProgress
 import eu.kanade.tachiyomi.util.lang.launchIO
 import eu.kanade.tachiyomi.util.storage.getUriCompat
 import eu.kanade.tachiyomi.util.storage.saveTo
+import eu.kanade.tachiyomi.util.system.acquireWakeLock
 import eu.kanade.tachiyomi.util.system.isServiceRunning
 import java.io.File
 import timber.log.Timber
@@ -40,10 +41,7 @@ class UpdaterService : Service() {
 
         startForeground(Notifications.ID_UPDATER, notifier.onDownloadStarted().build())
 
-        wakeLock = (getSystemService(Context.POWER_SERVICE) as PowerManager).newWakeLock(
-            PowerManager.PARTIAL_WAKE_LOCK, "${javaClass.name}:WakeLock"
-        )
-        wakeLock.acquire()
+        wakeLock = acquireWakeLock(javaClass.name)
     }
 
     /**
@@ -143,11 +141,10 @@ class UpdaterService : Service() {
             context.isServiceRunning(UpdaterService::class.java)
 
         /**
-         * Make a backup from library
+         * Downloads a new update and let the user install the new version from a notification.
          *
-         * @param context context of application
-         * @param uri path of Uri
-         * @param flags determines what to backup
+         * @param context the application context.
+         * @param url the url to the new update.
          */
         fun start(context: Context, url: String, title: String = context.getString(R.string.app_name)) {
             if (!isRunning(context)) {
diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsAdvancedController.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsAdvancedController.kt
index 8af6e3028c..f4ffd794d5 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsAdvancedController.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsAdvancedController.kt
@@ -3,12 +3,10 @@ package eu.kanade.tachiyomi.ui.setting
 import android.annotation.SuppressLint
 import android.app.Dialog
 import android.content.ActivityNotFoundException
-import android.content.Context.POWER_SERVICE
 import android.content.Intent
 import android.net.Uri
 import android.os.Build
 import android.os.Bundle
-import android.os.PowerManager
 import android.provider.Settings
 import androidx.preference.PreferenceScreen
 import com.afollestad.materialdialogs.MaterialDialog
@@ -28,6 +26,7 @@ import eu.kanade.tachiyomi.util.preference.preference
 import eu.kanade.tachiyomi.util.preference.summaryRes
 import eu.kanade.tachiyomi.util.preference.switchPreference
 import eu.kanade.tachiyomi.util.preference.titleRes
+import eu.kanade.tachiyomi.util.system.powerManager
 import eu.kanade.tachiyomi.util.system.toast
 import rx.Observable
 import rx.android.schedulers.AndroidSchedulers
@@ -96,8 +95,7 @@ class SettingsAdvancedController : SettingsController() {
 
                 onClick {
                     val packageName: String = context.packageName
-                    val pm = context.getSystemService(POWER_SERVICE) as PowerManager?
-                    if (!pm!!.isIgnoringBatteryOptimizations(packageName)) {
+                    if (!context.powerManager.isIgnoringBatteryOptimizations(packageName)) {
                         try {
                             val intent = Intent().apply {
                                 action = Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS
diff --git a/app/src/main/java/eu/kanade/tachiyomi/util/system/ContextExtensions.kt b/app/src/main/java/eu/kanade/tachiyomi/util/system/ContextExtensions.kt
index 8b1be08716..76c747a515 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/util/system/ContextExtensions.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/util/system/ContextExtensions.kt
@@ -147,6 +147,15 @@ val Context.connectivityManager: ConnectivityManager
 val Context.powerManager: PowerManager
     get() = getSystemService(Context.POWER_SERVICE) as PowerManager
 
+/**
+ * Convenience method to acquire a partial wake lock.
+ */
+fun Context.acquireWakeLock(tag: String): PowerManager.WakeLock {
+    val wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "$tag:WakeLock")
+    wakeLock.acquire()
+    return wakeLock
+}
+
 /**
  * Function used to send a local broadcast asynchronous
  *