diff --git a/app/src/main/java/com/stevesoltys/seedvault/App.kt b/app/src/main/java/com/stevesoltys/seedvault/App.kt
index f3403de79..84469065f 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/App.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/App.kt
@@ -2,6 +2,7 @@ package com.stevesoltys.seedvault
 
 import android.Manifest.permission.INTERACT_ACROSS_USERS_FULL
 import android.app.Application
+import android.app.backup.BackupManager
 import android.app.backup.BackupManager.PACKAGE_MANAGER_SENTINEL
 import android.app.backup.IBackupManager
 import android.content.Context
@@ -117,9 +118,10 @@ open class App : Application() {
 
 }
 
-const val MAGIC_PACKAGE_MANAGER = PACKAGE_MANAGER_SENTINEL
+const val MAGIC_PACKAGE_MANAGER: String = PACKAGE_MANAGER_SENTINEL
 const val ANCESTRAL_RECORD_KEY = "@ancestral_record@"
 const val GLOBAL_METADATA_KEY = "@meta@"
+const val ERROR_BACKUP_CANCELLED: Int = BackupManager.ERROR_BACKUP_CANCELLED
 
 // TODO this doesn't work for LineageOS as they do public debug builds
 fun isDebugBuild() = Build.TYPE == "userdebug"
diff --git a/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsManager.kt b/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsManager.kt
index 47176a091..b441ae227 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsManager.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsManager.kt
@@ -143,6 +143,15 @@ class SettingsManager(private val context: Context) {
 
     fun isBackupEnabled(packageName: String) = !blacklistedApps.contains(packageName)
 
+    /**
+     * Disables backup for an app. Similar to [onAppBackupStatusChanged].
+     */
+    fun disableBackup(packageName: String) {
+        if (blacklistedApps.add(packageName)) {
+            prefs.edit().putStringSet(PREF_KEY_BACKUP_APP_BLACKLIST, blacklistedApps).apply()
+        }
+    }
+
     fun isStorageBackupEnabled() = prefs.getBoolean(PREF_KEY_BACKUP_STORAGE, false)
 
     @UiThread
diff --git a/app/src/main/java/com/stevesoltys/seedvault/ui/notification/NotificationBackupObserver.kt b/app/src/main/java/com/stevesoltys/seedvault/ui/notification/NotificationBackupObserver.kt
index 47235213e..553587fd2 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/ui/notification/NotificationBackupObserver.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/ui/notification/NotificationBackupObserver.kt
@@ -1,15 +1,18 @@
 package com.stevesoltys.seedvault.ui.notification
 
 import android.app.backup.BackupProgress
+import android.app.backup.BackupTransport.AGENT_ERROR
 import android.app.backup.IBackupObserver
 import android.content.Context
 import android.content.pm.PackageManager.NameNotFoundException
 import android.util.Log
 import android.util.Log.INFO
 import android.util.Log.isLoggable
+import com.stevesoltys.seedvault.ERROR_BACKUP_CANCELLED
 import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.metadata.MetadataManager
+import com.stevesoltys.seedvault.settings.SettingsManager
 import com.stevesoltys.seedvault.transport.backup.BackupRequester
 import com.stevesoltys.seedvault.transport.backup.ExpectedAppTotals
 import org.koin.core.component.KoinComponent
@@ -26,9 +29,12 @@ internal class NotificationBackupObserver(
 
     private val nm: BackupNotificationManager by inject()
     private val metadataManager: MetadataManager by inject()
+    private val settingsManager: SettingsManager by inject()
     private var currentPackage: String? = null
     private var numPackages: Int = 0
 
+    private var errorPackageName: String? = null
+
     init {
         // Inform the notification manager that a backup has started
         // and inform about the expected numbers, so it can compute a total.
@@ -63,6 +69,16 @@ internal class NotificationBackupObserver(
         if (isLoggable(TAG, INFO)) {
             Log.i(TAG, "Completed. Target: $target, status: $status")
         }
+        // Apps that get killed while interacting with their [BackupAgent] cancel the entire backup.
+        // In order to prevent them from DoSing us, we remember them here to auto-disable them.
+        // We noticed that the same app behavior can cause a status of
+        // either AGENT_ERROR or ERROR_BACKUP_CANCELLED, so we need to handle both.
+        errorPackageName = if (status == AGENT_ERROR || status == ERROR_BACKUP_CANCELLED) {
+            target
+        } else {
+            null // To not disable apps by mistake, we reset it when getting a new non-error result.
+        }
+
         // often [onResult] gets called right away without any [onUpdate] call
         showProgressNotification(target)
     }
@@ -75,6 +91,15 @@ internal class NotificationBackupObserver(
      *   as a whole failed.
      */
     override fun backupFinished(status: Int) {
+        if (status == ERROR_BACKUP_CANCELLED) {
+            val packageName = errorPackageName
+            if (packageName == null) {
+                Log.e(TAG, "Backup got cancelled, but there we have no culprit :(")
+            } else {
+                Log.w(TAG, "App $packageName misbehaved, will disable backup for it...")
+                settingsManager.disableBackup(packageName)
+            }
+        }
         if (backupRequester.requestNext()) {
             if (isLoggable(TAG, INFO)) {
                 Log.i(TAG, "Backup finished $numPackages/$requestedPackages. Status: $status")