diff --git a/README.md b/README.md
index 65d194f..4db3065 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ Currently implemented (more or less):
 
 * Showing a notification with some caller info (positive/negative rating, category, number of negative reviews and such) when the phone's ringing. *Works offline.*
 * Loading and displaying a list of reviews for a number (accessed by pressing the notification). *Requires internet.*
-* Automatic blocking of unwanted calls (may not work on some devices; doesn't work on Android 9+). *Works offline.*
+* Automatic blocking of unwanted calls (may not work on some devices; may work as a system app on Android 9; doesn't work on Android 10+). *Works offline.*
 * Automatic update of the database (for offline use). *Requires internet.*
 
 
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index ca00c57..023a6f5 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -8,6 +8,10 @@
     <uses-permission android:name="android.permission.READ_CALL_LOG" />
     <uses-permission android:name="android.permission.CALL_PHONE" />
 
+    <!-- required for call blocking on Android 9, also requires to be installed as a system app -->
+    <uses-permission android:name="android.permission.MODIFY_PHONE_STATE"
+        tools:ignore="ProtectedPermissions" />
+
     <application
         android:name=".App"
         android:allowBackup="true"
diff --git a/fastlane/metadata/android/en-US/full_description.txt b/fastlane/metadata/android/en-US/full_description.txt
index ca6e5fd..601fa94 100644
--- a/fastlane/metadata/android/en-US/full_description.txt
+++ b/fastlane/metadata/android/en-US/full_description.txt
@@ -5,7 +5,7 @@ Features:
 
 * Showing a notification with some caller info (positive/negative rating, category, number of negative reviews and such) when the phone's ringing. ''Works offline.''
 * Loading and displaying a list of reviews for a number. ''Requires internet.''
-* Automatic blocking of unwanted calls (may not work on some devices; doesn't work on Android 9+). ''Works offline.''
+* Automatic blocking of unwanted calls (may not work on some devices; may work as a system app on Android 9; doesn't work on Android 10+). ''Works offline.''
 * Automatic update of the database (for offline use). ''Requires internet.''
 
 How to use: