diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/EdziennikNotification.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/EdziennikNotification.kt
index 0b413356..6b2b7533 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/EdziennikNotification.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/EdziennikNotification.kt
@@ -13,6 +13,7 @@ import androidx.core.app.NotificationCompat.PRIORITY_MIN
 import pl.szczodrzynski.edziennik.App
 import pl.szczodrzynski.edziennik.R
 import pl.szczodrzynski.edziennik.ext.Bundle
+import pl.szczodrzynski.edziennik.ext.pendingIntentFlag
 import pl.szczodrzynski.edziennik.receivers.SzkolnyReceiver
 import kotlin.math.roundToInt
 
@@ -40,14 +41,14 @@ class EdziennikNotification(val app: App) {
                 "task" to "TaskCancelRequest",
                 "taskId" to taskId
         ))
-        return PendingIntent.getBroadcast(app, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT) as PendingIntent
+        return PendingIntent.getBroadcast(app, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT or pendingIntentFlag()) as PendingIntent
     }
     private val closePendingIntent: PendingIntent
         get() {
             val intent = SzkolnyReceiver.getIntent(app, Bundle(
                     "task" to "ServiceCloseRequest"
             ))
-            return PendingIntent.getBroadcast(app, 0, intent, 0) as PendingIntent
+            return PendingIntent.getBroadcast(app, 0, intent, pendingIntentFlag()) as PendingIntent
         }
 
     private fun errorCountText(): String? {
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/task/PostNotifications.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/task/PostNotifications.kt
index 8b4682d6..41614394 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/task/PostNotifications.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/task/PostNotifications.kt
@@ -16,6 +16,7 @@ import pl.szczodrzynski.edziennik.data.db.entity.Notification.Companion.TYPE_SER
 import pl.szczodrzynski.edziennik.ext.Intent
 import pl.szczodrzynski.edziennik.ext.asBoldSpannable
 import pl.szczodrzynski.edziennik.ext.concat
+import pl.szczodrzynski.edziennik.ext.pendingIntentFlag
 import pl.szczodrzynski.edziennik.utils.models.Time
 import pl.szczodrzynski.edziennik.data.db.entity.Notification as AppNotification
 
@@ -92,7 +93,7 @@ class PostNotifications(val app: App, nList: List<AppNotification>) {
                 MainActivity::class.java,
                 "fragmentId" to MainActivity.DRAWER_ITEM_NOTIFICATIONS
         )
-        val summaryIntent = PendingIntent.getActivity(app, app.notificationChannelsManager.data.id, intent, PendingIntent.FLAG_ONE_SHOT)
+        val summaryIntent = PendingIntent.getActivity(app, app.notificationChannelsManager.data.id, intent, PendingIntent.FLAG_ONE_SHOT or pendingIntentFlag())
 
         // On Nougat or newer - show maximum 8 notifications
         // On Marshmallow or older - show maximum 4 notifications
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Notification.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Notification.kt
index e57e8efa..35208927 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Notification.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Notification.kt
@@ -13,6 +13,7 @@ import com.google.gson.JsonObject
 import com.mikepenz.iconics.typeface.IIcon
 import com.mikepenz.iconics.typeface.library.community.material.CommunityMaterial
 import pl.szczodrzynski.edziennik.MainActivity
+import pl.szczodrzynski.edziennik.ext.pendingIntentFlag
 
 @Entity(tableName = "notifications")
 data class Notification(
@@ -98,7 +99,7 @@ data class Notification(
     fun getPendingIntent(context: Context): PendingIntent {
         val intent = Intent(context, MainActivity::class.java)
         fillIntent(intent)
-        return PendingIntent.getActivity(context, id.toInt(), intent, PendingIntent.FLAG_ONE_SHOT)
+        return PendingIntent.getActivity(context, id.toInt(), intent, PendingIntent.FLAG_ONE_SHOT or pendingIntentFlag())
     }
 
     fun getLargeIcon(): IIcon = when (type) {
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ext/MiscExtensions.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ext/MiscExtensions.kt
index 22ed9e43..df931fbd 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ext/MiscExtensions.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ext/MiscExtensions.kt
@@ -4,7 +4,9 @@
 
 package pl.szczodrzynski.edziennik.ext
 
+import android.app.PendingIntent
 import android.database.Cursor
+import android.os.Build
 import androidx.core.database.getIntOrNull
 import androidx.core.database.getLongOrNull
 import androidx.core.database.getStringOrNull
@@ -64,3 +66,9 @@ inline fun <A, B, R> ifNotNull(a: A?, b: B?, code: (A, B) -> R): R? {
 }
 
 infix fun Int.hasSet(what: Int) = this and what == what
+
+fun pendingIntentFlag(): Int {
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
+        return PendingIntent.FLAG_IMMUTABLE
+    return 0
+}
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/sync/UpdateWorker.kt b/app/src/main/java/pl/szczodrzynski/edziennik/sync/UpdateWorker.kt
index 5325d533..0df0bc83 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/sync/UpdateWorker.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/sync/UpdateWorker.kt
@@ -21,6 +21,7 @@ import pl.szczodrzynski.edziennik.data.api.szkolny.response.Update
 import pl.szczodrzynski.edziennik.ext.DAY
 import pl.szczodrzynski.edziennik.ext.concat
 import pl.szczodrzynski.edziennik.ext.formatDate
+import pl.szczodrzynski.edziennik.ext.pendingIntentFlag
 import pl.szczodrzynski.edziennik.utils.Utils
 import pl.szczodrzynski.edziennik.utils.html.BetterHtml
 import java.util.concurrent.TimeUnit
@@ -109,7 +110,7 @@ class UpdateWorker(val context: Context, val params: WorkerParameters) : Worker(
                 }
 
                 val notificationIntent = Intent(app, UpdateDownloaderService::class.java)
-                val pendingIntent = PendingIntent.getService(app, 0, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT)
+                val pendingIntent = PendingIntent.getService(app, 0, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT or pendingIntentFlag())
                 val notification = NotificationCompat.Builder(app, app.notificationChannelsManager.updates.key)
                         .setContentTitle(app.getString(R.string.notification_updates_title))
                         .setContentText(app.getString(R.string.notification_updates_text, update.versionName))
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/luckynumber/WidgetLuckyNumberProvider.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/luckynumber/WidgetLuckyNumberProvider.kt
index e6332115..40b40d5c 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/luckynumber/WidgetLuckyNumberProvider.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/luckynumber/WidgetLuckyNumberProvider.kt
@@ -16,6 +16,7 @@ import pl.szczodrzynski.edziennik.App
 import pl.szczodrzynski.edziennik.MainActivity
 import pl.szczodrzynski.edziennik.R
 import pl.szczodrzynski.edziennik.ext.getJsonObject
+import pl.szczodrzynski.edziennik.ext.pendingIntentFlag
 import pl.szczodrzynski.edziennik.ui.widgets.WidgetConfig
 import pl.szczodrzynski.edziennik.utils.Utils
 import pl.szczodrzynski.edziennik.utils.models.Date
@@ -81,7 +82,7 @@ class WidgetLuckyNumberProvider : AppWidgetProvider() {
             val openIntent = Intent(context, MainActivity::class.java)
             openIntent.action = Intent.ACTION_MAIN
             openIntent.putExtra("fragmentId", MainActivity.DRAWER_ITEM_HOME)
-            val openPendingIntent = PendingIntent.getActivity(context, 0, openIntent, 0)
+            val openPendingIntent = PendingIntent.getActivity(context, 0, openIntent, pendingIntentFlag())
             views.setOnClickPendingIntent(R.id.widgetLuckyNumberRoot, openPendingIntent)
 
             appWidgetManager.updateAppWidget(appWidgetId, views)
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/notifications/WidgetNotificationsProvider.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/notifications/WidgetNotificationsProvider.kt
index b2ac08d7..dc4eb02e 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/notifications/WidgetNotificationsProvider.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/notifications/WidgetNotificationsProvider.kt
@@ -22,6 +22,7 @@ import pl.szczodrzynski.edziennik.MainActivity
 import pl.szczodrzynski.edziennik.R
 import pl.szczodrzynski.edziennik.ext.Bundle
 import pl.szczodrzynski.edziennik.ext.getJsonObject
+import pl.szczodrzynski.edziennik.ext.pendingIntentFlag
 import pl.szczodrzynski.edziennik.receivers.SzkolnyReceiver
 import pl.szczodrzynski.edziennik.ui.widgets.WidgetConfig
 
@@ -47,7 +48,7 @@ class WidgetNotificationsProvider : AppWidgetProvider() {
             val syncIntent = SzkolnyReceiver.getIntent(context, Bundle(
                     "task" to "SyncRequest"
             ))
-            val syncPendingIntent = PendingIntent.getBroadcast(context, 0, syncIntent, 0)
+            val syncPendingIntent = PendingIntent.getBroadcast(context, 0, syncIntent, pendingIntentFlag())
             views.setOnClickPendingIntent(R.id.widgetNotificationsSync, syncPendingIntent)
 
             views.setImageViewBitmap(
@@ -68,13 +69,13 @@ class WidgetNotificationsProvider : AppWidgetProvider() {
 
             val itemIntent = Intent(context, MainActivity::class.java)
             itemIntent.action = Intent.ACTION_MAIN
-            val itemPendingIntent = PendingIntent.getActivity(context, 0, itemIntent, 0)
+            val itemPendingIntent = PendingIntent.getActivity(context, 0, itemIntent, pendingIntentFlag())
             views.setPendingIntentTemplate(R.id.widgetNotificationsListView, itemPendingIntent)
 
             val headerIntent = Intent(context, MainActivity::class.java)
             headerIntent.action = Intent.ACTION_MAIN
             headerIntent.putExtra("fragmentId", MainActivity.DRAWER_ITEM_NOTIFICATIONS)
-            val headerPendingIntent = PendingIntent.getActivity(context, 0, headerIntent, 0)
+            val headerPendingIntent = PendingIntent.getActivity(context, 0, headerIntent, pendingIntentFlag())
             views.setOnClickPendingIntent(R.id.widgetNotificationsHeader, headerPendingIntent)
 
             appWidgetManager.updateAppWidget(appWidgetId, views)
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/timetable/WidgetTimetableProvider.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/timetable/WidgetTimetableProvider.kt
index 8c87ad30..87da09a8 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/timetable/WidgetTimetableProvider.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/widgets/timetable/WidgetTimetableProvider.kt
@@ -31,6 +31,7 @@ import pl.szczodrzynski.edziennik.data.db.entity.Lesson
 import pl.szczodrzynski.edziennik.data.db.entity.Lesson.Companion.TYPE_NO_LESSONS
 import pl.szczodrzynski.edziennik.ext.filterOutArchived
 import pl.szczodrzynski.edziennik.ext.getJsonObject
+import pl.szczodrzynski.edziennik.ext.pendingIntentFlag
 import pl.szczodrzynski.edziennik.ui.widgets.LessonDialogActivity
 import pl.szczodrzynski.edziennik.ui.widgets.WidgetConfig
 import pl.szczodrzynski.edziennik.utils.models.Date
@@ -53,8 +54,8 @@ class WidgetTimetableProvider : AppWidgetProvider() {
             return getPendingSelfIntent(context, intent)
         }
 
-        fun getPendingSelfIntent(context: Context, intent: Intent): PendingIntent {
-            return PendingIntent.getBroadcast(context, 0, intent, 0)
+        private fun getPendingSelfIntent(context: Context, intent: Intent): PendingIntent {
+            return PendingIntent.getBroadcast(context, 0, intent, pendingIntentFlag())
         }
 
         fun drawableToBitmap(drawable: Drawable): Bitmap {
@@ -111,7 +112,7 @@ class WidgetTimetableProvider : AppWidgetProvider() {
             refreshIntent.action = AppWidgetManager.ACTION_APPWIDGET_UPDATE
             refreshIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, appWidgetIds)
             val refreshPendingIntent = PendingIntent.getBroadcast(context,
-                    0, refreshIntent, PendingIntent.FLAG_UPDATE_CURRENT)
+                    0, refreshIntent, PendingIntent.FLAG_UPDATE_CURRENT or pendingIntentFlag())
             views.setOnClickPendingIntent(R.id.widgetTimetableRefresh, refreshPendingIntent)
 
             views.setOnClickPendingIntent(R.id.widgetTimetableSync, getPendingSelfIntent(context, ACTION_SYNC_DATA))
@@ -394,7 +395,7 @@ class WidgetTimetableProvider : AppWidgetProvider() {
             }
         }
         headerIntent.putExtra("fragmentId", MainActivity.DRAWER_ITEM_TIMETABLE)
-        val headerPendingIntent = PendingIntent.getActivity(app, appWidgetId, headerIntent, 0)
+        val headerPendingIntent = PendingIntent.getActivity(app, appWidgetId, headerIntent, pendingIntentFlag())
         views.setOnClickPendingIntent(R.id.widgetTimetableHeader, headerPendingIntent)
 
         timetables!!.put(appWidgetId, models)
@@ -408,7 +409,7 @@ class WidgetTimetableProvider : AppWidgetProvider() {
         // create an intent used to display the lesson details dialog
         val itemIntent = Intent(app, LessonDialogActivity::class.java)
         itemIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK/* or Intent.FLAG_ACTIVITY_CLEAR_TASK*/)
-        val itemPendingIntent = PendingIntent.getActivity(app, appWidgetId, itemIntent, 0)
+        val itemPendingIntent = PendingIntent.getActivity(app, appWidgetId, itemIntent, pendingIntentFlag())
         views.setPendingIntentTemplate(R.id.widgetTimetableListView, itemPendingIntent)
 
         if (!unified)
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/utils/managers/UserActionManager.kt b/app/src/main/java/pl/szczodrzynski/edziennik/utils/managers/UserActionManager.kt
index 7bd69545..dbe05325 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/utils/managers/UserActionManager.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/utils/managers/UserActionManager.kt
@@ -19,6 +19,7 @@ import pl.szczodrzynski.edziennik.data.api.events.UserActionRequiredEvent
 import pl.szczodrzynski.edziennik.data.api.models.ApiError
 import pl.szczodrzynski.edziennik.ext.Intent
 import pl.szczodrzynski.edziennik.ext.JsonObject
+import pl.szczodrzynski.edziennik.ext.pendingIntentFlag
 import pl.szczodrzynski.edziennik.ui.captcha.LibrusCaptchaDialog
 
 class UserActionManager(val app: App) {
@@ -55,7 +56,7 @@ class UserActionManager(val app: App) {
                 "profileId" to (apiError.profileId ?: -1),
                 "type" to type
         )
-        val pendingIntent = PendingIntent.getActivity(app, System.currentTimeMillis().toInt(), intent, PendingIntent.FLAG_ONE_SHOT)
+        val pendingIntent = PendingIntent.getActivity(app, System.currentTimeMillis().toInt(), intent, PendingIntent.FLAG_ONE_SHOT or pendingIntentFlag())
 
         val notification = NotificationCompat.Builder(app, app.notificationChannelsManager.userAttention.key)
                 .setContentTitle(app.getString(R.string.notification_user_action_required_title))
diff --git a/app/src/play-not/java/pl/szczodrzynski/edziennik/sync/UpdateDownloaderService.kt b/app/src/play-not/java/pl/szczodrzynski/edziennik/sync/UpdateDownloaderService.kt
index 31c24d2f..93881939 100644
--- a/app/src/play-not/java/pl/szczodrzynski/edziennik/sync/UpdateDownloaderService.kt
+++ b/app/src/play-not/java/pl/szczodrzynski/edziennik/sync/UpdateDownloaderService.kt
@@ -115,6 +115,7 @@ class UpdateDownloaderService : IntentService(UpdateDownloaderService::class.jav
             Toast.makeText(app, "Nie można znaleźć katalogu docelowego. Pobierz aktualizację ręcznie z Google Play.", Toast.LENGTH_LONG).show()
             return
         }
+        Toast.makeText(app, "Pobieranie aktualizacji Szkolny.eu ${update.versionName}", Toast.LENGTH_LONG).show()
         downloadId = downloadManager.enqueue(request)
     }
 }