diff --git a/mod/display.php b/mod/display.php
index 6abf4c019d..6b30391d65 100644
--- a/mod/display.php
+++ b/mod/display.php
@@ -177,9 +177,9 @@ function display_content(App $a, $update = false, $update_uid = 0)
 		$item = Post::selectFirst(['uid', 'parent-uri-id'], ['uri-id' => $uri_id, 'uid' => $update_uid]);
 		if (!empty($item)) {
 			if ($item['uid'] != 0) {
-				$a->profile_owner = intval($item['uid']);
+				$a->setProfileOwner($item['uid']);
 			} else {
-				$a->profile_owner = intval($update_uid);
+				$a->setProfileOwner($update_uid);
 			}
 			$parent_uri_id = $item['parent-uri-id'];
 		}
diff --git a/mod/notes.php b/mod/notes.php
index 2759164bc4..945d0c935d 100644
--- a/mod/notes.php
+++ b/mod/notes.php
@@ -64,11 +64,11 @@ function notes_content(App $a, $update = false)
 			'acl_data' => '',
 		];
 
-		$o .= status_editor($a, $x, $a->contact_id);
+		$o .= status_editor($a, $x, $a->getContactId());
 	}
 
 	$condition = ['uid' => local_user(), 'post-type' => Item::PT_PERSONAL_NOTE, 'gravity' => GRAVITY_PARENT,
-		'contact-id'=> $a->contact_id];
+		'contact-id'=> $a->getContactId()];
 
 	if (DI::mode()->isMobile()) {
 		$itemsPerPage = DI::pConfig()->get(local_user(), 'system', 'itemspage_mobile_network',
diff --git a/mod/redir.php b/mod/redir.php
index ca0fe71a82..557bbe4443 100644
--- a/mod/redir.php
+++ b/mod/redir.php
@@ -58,7 +58,7 @@ function redir_init(App $a) {
 
 	$contact_url = $contact['url'];
 
-	if (!empty($a->contact_id) && $a->contact_id == $cid) {
+	if (!empty($a->getContactId()) && $a->getContactId() == $cid) {
 		// Local user is already authenticated.
 		redir_check_url($contact_url, $url);
 		$a->redirect($url ?: $contact_url);
@@ -73,7 +73,7 @@ function redir_init(App $a) {
 			$cid = $contact['id'];
 		}
 
-		if (!empty($a->contact_id) && $a->contact_id == $cid) {
+		if (!empty($a->getContactId()) && $a->getContactId() == $cid) {
 			// Local user is already authenticated.
 			redir_check_url($contact_url, $url);
 			$target_url = $url ?: $contact_url;
diff --git a/src/App.php b/src/App.php
index aba922804c..8190bcbaee 100644
--- a/src/App.php
+++ b/src/App.php
@@ -56,8 +56,9 @@ use Psr\Log\LoggerInterface;
  */
 class App
 {
-	public $profile_owner;
-	public $contact_id;
+	private $profile_owner;
+	private $contact_id;
+
 	public $user;
 	public $data = [];
 	/** @deprecated 2019.09 - use App\Arguments->getArgv() or Arguments->get() */
@@ -129,6 +130,26 @@ class App
 	 */
 	private $pConfig;
 
+	public function setProfileOwner(int $owner_id)
+	{
+		$this->profile_owner = $owner_id;
+	}
+
+	public function getProfileOwner()
+	{
+		return $this->profile_owner;
+	}
+
+	public function setContactId(int $contact_id)
+	{
+		$this->contact_id = $contact_id;
+	}
+
+	public function getContactId()
+	{
+		return $this->contact_id;
+	}
+
 	/**
 	 * Returns the current config cache of this node
 	 *
diff --git a/src/Content/Widget.php b/src/Content/Widget.php
index 88afbe9e52..a899644c3c 100644
--- a/src/Content/Widget.php
+++ b/src/Content/Widget.php
@@ -334,7 +334,7 @@ class Widget
 	{
 		$a = DI::app();
 
-		$uid = intval($a->profile_owner);
+		$uid = intval($a->getProfileOwner());
 
 		if (!Feature::isEnabled($uid, 'categories')) {
 			return '';
diff --git a/src/Model/Item.php b/src/Model/Item.php
index 477d8f3bea..327c60d5cf 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -2685,7 +2685,7 @@ class Item
 					continue;
 				}
 
-				if ((local_user() == $item['uid']) && ($item['private'] == self::PRIVATE) && ($item['contact-id'] != $app->contact_id) && ($item['network'] == Protocol::DFRN)) {
+				if ((local_user() == $item['uid']) && ($item['private'] == self::PRIVATE) && ($item['contact-id'] != $app->getContactId()) && ($item['network'] == Protocol::DFRN)) {
 					$img_url = 'redir/' . $item['contact-id'] . '?url=' . urlencode($mtch[1]);
 					$item['body'] = str_replace($mtch[0], '[img]' . $img_url . '[/img]', $item['body']);
 				}
diff --git a/src/Model/Profile.php b/src/Model/Profile.php
index 980cd204e3..62df630dc8 100644
--- a/src/Model/Profile.php
+++ b/src/Model/Profile.php
@@ -219,13 +219,13 @@ class Profile
 			return [];
 		}
 
-		$a->profile_owner = $profile['uid'];
+		$a->setProfileOwner($profile['uid']);
 
 		DI::page()['title'] = $profile['name'] . ' @ ' . DI::config()->get('config', 'sitename');
 
 		if (!DI::pConfig()->get(local_user(), 'system', 'always_my_theme')) {
 			$a->setCurrentTheme($profile['theme']);
-			$a->setCurrentMobileTheme(DI::pConfig()->get($a->profile_owner, 'system', 'mobile_theme'));
+			$a->setCurrentMobileTheme(DI::pConfig()->get($a->getProfileOwner(), 'system', 'mobile_theme'));
 		}
 
 		/*
@@ -768,7 +768,7 @@ class Profile
 
 		Session::setVisitorsContacts();
 
-		$a->contact_id = $visitor['id'];
+		$a->setContactId($visitor['id']);
 
 		Logger::info('Authenticated visitor', ['url' => $visitor['url']]);
 
@@ -829,7 +829,7 @@ class Profile
 		 */
 		Hook::callAll('magic_auth_success', $arr);
 
-		$a->contact_id = $arr['visitor']['id'];
+		$a->setContactId($arr['visitor']['id']);
 
 		info(DI::l10n()->t('OpenWebAuth: %1$s welcomes %2$s', DI::baseUrl()->getHostname(), $visitor['name']));
 
@@ -871,7 +871,7 @@ class Profile
 	 */
 	public static function getThemeUid(App $a)
 	{
-		$uid = !empty($a->profile_owner) ? intval($a->profile_owner) : 0;
+		$uid = !empty($a->getProfileOwner()) ? intval($a->getProfileOwner()) : 0;
 		if (local_user() && (DI::pConfig()->get(local_user(), 'system', 'always_my_theme') || !$uid)) {
 			return local_user();
 		}
diff --git a/src/Module/Contact/Poke.php b/src/Module/Contact/Poke.php
index f8f58fe48c..955d4bab0e 100644
--- a/src/Module/Contact/Poke.php
+++ b/src/Module/Contact/Poke.php
@@ -60,7 +60,7 @@ class Poke extends BaseModule
 		$deny_cid      = ($private ? '' : $a->user['deny_cid']);
 		$deny_gid      = ($private ? '' : $a->user['deny_gid']);
 
-		$actor = Contact::getById($a->contact_id);
+		$actor = Contact::getById($a->getContactId());
 
 		$uri = Model\Item::newURI($uid);
 
diff --git a/src/Module/Item/Compose.php b/src/Module/Item/Compose.php
index 21dd5625c1..e06c4ba0c1 100644
--- a/src/Module/Item/Compose.php
+++ b/src/Module/Item/Compose.php
@@ -87,7 +87,7 @@ class Compose extends BaseModule
 				$compose_title = DI::l10n()->t('Compose new personal note');
 				$type = 'note';
 				$doesFederate = false;
-				$contact_allow_list = [$a->contact_id];
+				$contact_allow_list = [$a->getContactId()];
 				$group_allow_list = [];
 				$contact_deny_list = [];
 				$group_deny_list = [];
@@ -130,7 +130,7 @@ class Compose extends BaseModule
 		DI::page()->registerFooterScript(Theme::getPathForFile('js/linkPreview.js'));
 		DI::page()->registerFooterScript(Theme::getPathForFile('js/compose.js'));
 
-		$contact = Contact::getById($a->contact_id);
+		$contact = Contact::getById($a->getContactId());
 
 		$tpl = Renderer::getMarkupTemplate('item/compose.tpl');
 		return Renderer::replaceMacros($tpl, [
diff --git a/src/Module/Magic.php b/src/Module/Magic.php
index 81d6def338..5b4676dd56 100644
--- a/src/Module/Magic.php
+++ b/src/Module/Magic.php
@@ -65,7 +65,7 @@ class Magic extends BaseModule
 		$contact = DBA::selectFirst('contact', ['id', 'nurl', 'url'], ['id' => $cid]);
 
 		// Redirect if the contact is already authenticated on this site.
-		if (!empty($a->contact_id) && strpos($contact['nurl'], Strings::normaliseLink(DI::baseUrl()->get())) !== false) {
+		if (!empty($a->getContactId()) && strpos($contact['nurl'], Strings::normaliseLink(DI::baseUrl()->get())) !== false) {
 			if ($test) {
 				$ret['success'] = true;
 				$ret['message'] .= 'Local site - you are already authenticated.' . EOL;
diff --git a/src/Module/Update/Profile.php b/src/Module/Update/Profile.php
index 4ec6a977b2..e9e8681af5 100644
--- a/src/Module/Update/Profile.php
+++ b/src/Module/Update/Profile.php
@@ -40,18 +40,18 @@ class Profile extends BaseModule
 		$a = DI::app();
 
 		// Ensure we've got a profile owner if updating.
-		$a->profile_owner = intval($_GET['p'] ?? 0);
+		$a->setProfileOwner($_GET['p'] ?? 0);
 
-		if (DI::config()->get('system', 'block_public') && !local_user() && !Session::getRemoteContactID($a->profile_owner)) {
+		if (DI::config()->get('system', 'block_public') && !local_user() && !Session::getRemoteContactID($a->getProfileOwner())) {
 			throw new ForbiddenException();
 		}
 
-		$remote_contact = Session::getRemoteContactID($a->profile_owner);
-		$is_owner = local_user() == $a->profile_owner;
-		$last_updated_key = "profile:" . $a->profile_owner . ":" . local_user() . ":" . $remote_contact;
+		$remote_contact = Session::getRemoteContactID($a->getProfileOwner());
+		$is_owner = local_user() == $a->getProfileOwner();
+		$last_updated_key = "profile:" . $a->getProfileOwner() . ":" . local_user() . ":" . $remote_contact;
 
 		if (!$is_owner && !$remote_contact) {
-			$user = User::getById($a->profile_owner, ['hidewall']);
+			$user = User::getById($a->getProfileOwner(), ['hidewall']);
 			if ($user['hidewall']) {
 				throw new ForbiddenException(DI::l10n()->t('Access to this profile has been restricted.'));
 			}
@@ -64,7 +64,7 @@ class Profile extends BaseModule
 		}
 
 		// Get permissions SQL - if $remote_contact is true, our remote user has been pre-verified and we already have fetched his/her groups
-		$sql_extra = Item::getPermissionsSQLByUserId($a->profile_owner);
+		$sql_extra = Item::getPermissionsSQLByUserId($a->getProfileOwner());
 
 		$last_updated_array = Session::get('last_updated', []);
 
@@ -88,7 +88,7 @@ class Profile extends BaseModule
 				AND `visible` AND (NOT `deleted` OR `gravity` = ?)
 				AND `wall` $sql_extra4 $sql_extra
 			GROUP BY `parent-uri-id` ORDER BY `received` DESC",
-			$a->profile_owner,
+			$a->getProfileOwner(),
 			GRAVITY_ACTIVITY
 		);
 
@@ -101,7 +101,7 @@ class Profile extends BaseModule
 		$last_updated_array[$last_updated_key] = time();
 		Session::set('last_updated', $last_updated_array);
 
-		if ($is_owner && !$a->profile_owner && !DI::config()->get('theme', 'hide_eventlist')) {
+		if ($is_owner && !$a->getProfileOwner() && !DI::config()->get('theme', 'hide_eventlist')) {
 			$o .= ProfileModel::getBirthdays();
 			$o .= ProfileModel::getEventsReminderHTML();
 		}
@@ -115,7 +115,7 @@ class Profile extends BaseModule
 
 		$items = DBA::toArray($items_stmt);
 
-		$o .= conversation($a, $items, 'profile', $a->profile_owner, false, 'received', $a->profile_owner);
+		$o .= conversation($a, $items, 'profile', $a->getProfileOwner(), false, 'received', $a->getProfileOwner());
 
 		System::htmlUpdateExit($o);
 	}
diff --git a/src/Object/Post.php b/src/Object/Post.php
index a56a73a266..a7071ad794 100644
--- a/src/Object/Post.php
+++ b/src/Object/Post.php
@@ -936,7 +936,7 @@ class Post
 			$uid = $conv->getProfileOwner();
 			$parent_uid = $this->getDataValue('uid');
 
-			$contact = Contact::getById($a->contact_id);
+			$contact = Contact::getById($a->getContactId());
 
 			$default_text = $this->getDefaultText();
 
diff --git a/src/Object/Thread.php b/src/Object/Thread.php
index a73803b525..a848586fe5 100644
--- a/src/Object/Thread.php
+++ b/src/Object/Thread.php
@@ -79,11 +79,11 @@ class Thread
 				$this->writable = true;
 				break;
 			case 'profile':
-				$this->profile_owner = $a->profile_owner;
+				$this->profile_owner = $a->getProfileOwner();
 				$this->writable = Security::canWriteToUserWall($this->profile_owner);
 				break;
 			case 'display':
-				$this->profile_owner = $a->profile_owner;
+				$this->profile_owner = $a->getProfileOwner();
 				$this->writable = Security::canWriteToUserWall($this->profile_owner) || $writable;
 				break;
 			case 'community':
diff --git a/src/Security/Authentication.php b/src/Security/Authentication.php
index 29ea4621c6..3ad9a28999 100644
--- a/src/Security/Authentication.php
+++ b/src/Security/Authentication.php
@@ -144,7 +144,7 @@ class Authentication
 			if ($this->session->get('visitor_id') && !$this->session->get('uid')) {
 				$contact = $this->dba->selectFirst('contact', ['id'], ['id' => $this->session->get('visitor_id')]);
 				if ($this->dba->isResult($contact)) {
-					$a->contact_id = $contact['id'];
+					$a->setContactId($contact['id']);
 				}
 			}
 
@@ -312,7 +312,7 @@ class Authentication
 
 		$contact = $this->dba->selectFirst('contact', ['id'], ['uid' => $user_record['uid'], 'self' => true]);
 		if ($this->dba->isResult($contact)) {
-			$a->contact_id = $contact['id'];
+			$a->setContactId($contact['id']);
 			$this->session->set('cid', $contact['id']);
 		}