diff --git a/.php_cs b/.php_cs
index f7a56ff..7f81780 100644
--- a/.php_cs
+++ b/.php_cs
@@ -8,7 +8,7 @@ $finder = PhpCsFixer\Finder::create()
 
 return PhpCsFixer\Config::create()
     ->setRules([
-        'native_function_invocation' => true,
+        'native_function_invocation' => ['include' => ['@all']],
 		'native_constant_invocation' => true,
     ])
     ->setFinder($finder)
diff --git a/activitypub.php b/activitypub.php
index e6a5539..fe834cd 100644
--- a/activitypub.php
+++ b/activitypub.php
@@ -72,7 +72,7 @@ function init() {
 		return '\Activitypub\Rest\Server';
 	} );
 }
-add_action( 'plugins_loaded', '\Activitypub\init' );
+\add_action( 'plugins_loaded', '\Activitypub\init' );
 
 /**
  * Add rewrite rules
diff --git a/includes/class-activitypub.php b/includes/class-activitypub.php
index 49e022a..e3b63ee 100644
--- a/includes/class-activitypub.php
+++ b/includes/class-activitypub.php
@@ -117,7 +117,7 @@ class Activitypub {
 		} elseif ( 'publish' === $new_status ) {
 			\wp_schedule_single_event( \time(), 'activitypub_send_update_activity', array( $post->ID ) );
 		} elseif ( 'trash' === $new_status ) {
-			\wp_schedule_single_event( \time(), 'activitypub_send_delete_activity', array( get_permalink( $post ) ) );
+			\wp_schedule_single_event( \time(), 'activitypub_send_delete_activity', array( \get_permalink( $post ) ) );
 		}
 	}
 
diff --git a/includes/class-admin.php b/includes/class-admin.php
index 0dca896..b9b7d59 100644
--- a/includes/class-admin.php
+++ b/includes/class-admin.php
@@ -30,7 +30,7 @@ class Admin {
 
 		\add_action( 'load-' . $settings_page, array( '\Activitypub\Admin', 'add_settings_help_tab' ) );
 
-		$followers_list_page = \add_users_page( \__( 'Followers', 'activitypub' ), __( 'Followers (Fediverse)', 'activitypub' ), 'read', 'activitypub-followers-list', array( '\Activitypub\Admin', 'followers_list_page' ) );
+		$followers_list_page = \add_users_page( \__( 'Followers', 'activitypub' ), \__( 'Followers (Fediverse)', 'activitypub' ), 'read', 'activitypub-followers-list', array( '\Activitypub\Admin', 'followers_list_page' ) );
 
 		\add_action( 'load-' . $followers_list_page, array( '\Activitypub\Admin', 'add_followers_list_help_tab' ) );
 	}
diff --git a/includes/functions.php b/includes/functions.php
index 982d740..b80ad99 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -157,7 +157,7 @@ function get_inbox_by_actor( $actor ) {
 		return $metadata['inbox'];
 	}
 
-	return new \WP_Error( 'activitypub_no_inbox', __( 'No "Inbox" found', 'activitypub' ), $metadata );
+	return new \WP_Error( 'activitypub_no_inbox', \__( 'No "Inbox" found', 'activitypub' ), $metadata );
 }
 
 /**
@@ -253,13 +253,13 @@ function url_to_authorid( $url ) {
 	global $wp_rewrite;
 
 	// check if url hase the same host
-	if ( wp_parse_url( site_url(), \PHP_URL_HOST ) !== wp_parse_url( $url, \PHP_URL_HOST ) ) {
+	if ( \wp_parse_url( \site_url(), \PHP_URL_HOST ) !== \wp_parse_url( $url, \PHP_URL_HOST ) ) {
 		return 0;
 	}
 
 	// first, check to see if there is a 'author=N' to match against
 	if ( \preg_match( '/[?&]author=(\d+)/i', $url, $values ) ) {
-		$id = absint( $values[1] );
+		$id = \absint( $values[1] );
 		if ( $id ) {
 			return $id;
 		}
@@ -279,7 +279,7 @@ function url_to_authorid( $url ) {
 
 	// match the rewrite rule with the passed url
 	if ( \preg_match( '/https?:\/\/(.+)' . \preg_quote( $author_regexp, '/' ) . '([^\/]+)/i', $url, $match ) ) {
-		$user = get_user_by( 'slug', $match[2] );
+		$user = \get_user_by( 'slug', $match[2] );
 		if ( $user ) {
 			return $user->ID;
 		}
diff --git a/includes/rest/class-nodeinfo.php b/includes/rest/class-nodeinfo.php
index 9d5101b..5464e08 100644
--- a/includes/rest/class-nodeinfo.php
+++ b/includes/rest/class-nodeinfo.php
@@ -105,7 +105,7 @@ class Nodeinfo {
 
 		$nodeinfo['version'] = '1.0';
 		$nodeinfo['server'] = array(
-			'baseUrl' => home_url( '/' ),
+			'baseUrl' => \home_url( '/' ),
 			'name' => \get_bloginfo( 'name' ),
 			'software' => 'wordpress',
 			'version' => \get_bloginfo( 'version' ),
diff --git a/includes/rest/class-outbox.php b/includes/rest/class-outbox.php
index a43b74e..65cc3ba 100644
--- a/includes/rest/class-outbox.php
+++ b/includes/rest/class-outbox.php
@@ -42,7 +42,7 @@ class Outbox {
 		$author  = \get_user_by( 'ID', $user_id );
 
 		if ( ! $author ) {
-			return new \WP_Error( 'rest_invalid_param', __( 'User not found', 'activitypub' ), array(
+			return new \WP_Error( 'rest_invalid_param', \__( 'User not found', 'activitypub' ), array(
 				'status' => 404,
 				'params' => array(
 					'user_id' => \__( 'User not found', 'activitypub' ),
diff --git a/includes/rest/class-server.php b/includes/rest/class-server.php
index 841c6ba..6c68621 100644
--- a/includes/rest/class-server.php
+++ b/includes/rest/class-server.php
@@ -24,7 +24,7 @@ class Server extends \WP_REST_Server {
 		}
 
 		// make request filterable
-		$request = apply_filters( 'activitypub_pre_dispatch_request', $request );
+		$request = \apply_filters( 'activitypub_pre_dispatch_request', $request );
 
 		return parent::dispatch( $request );
 	}
diff --git a/templates/json-author.php b/templates/json-author.php
index bfe4e97..a16de2f 100644
--- a/templates/json-author.php
+++ b/templates/json-author.php
@@ -31,7 +31,7 @@ $json->outbox = \get_rest_url( null, "/activitypub/1.0/users/$author_id/outbox"
 $json->followers = \get_rest_url( null, "/activitypub/1.0/users/$author_id/followers" );
 $json->following = \get_rest_url( null, "/activitypub/1.0/users/$author_id/following" );
 
-$json->manuallyApprovesFollowers = \apply_filters( 'activitypub_json_manually_approves_followers', __return_false() ); // phpcs:ignore
+$json->manuallyApprovesFollowers = \apply_filters( 'activitypub_json_manually_approves_followers', \__return_false() ); // phpcs:ignore
 
 // phpcs:ignore
 $json->publicKey = array(
@@ -45,7 +45,7 @@ $json->attachment = array();
 
 $json->attachment[] = array(
 	'type' => 'PropertyValue',
-	'name' => __( 'Blog', 'activitypub' ),
+	'name' => \__( 'Blog', 'activitypub' ),
 	'value' => \html_entity_decode(
 		'<a rel="me" title="' . \esc_attr( \home_url( '/' ) ) . '" target="_blank" href="' . \home_url( '/' ) . '">' . \wp_parse_url( \home_url( '/' ), \PHP_URL_HOST ) . '</a>',
 		\ENT_QUOTES,
@@ -55,7 +55,7 @@ $json->attachment[] = array(
 
 $json->attachment[] = array(
 	'type' => 'PropertyValue',
-	'name' => __( 'Profile', 'activitypub' ),
+	'name' => \__( 'Profile', 'activitypub' ),
 	'value' => \html_entity_decode(
 		'<a rel="me" title="' . \esc_attr( \get_author_posts_url( $author_id ) ) . '" target="_blank" href="' . \get_author_posts_url( $author_id ) . '">' . \wp_parse_url( \get_author_posts_url( $author_id ), \PHP_URL_HOST ) . '</a>',
 		\ENT_QUOTES,
@@ -66,7 +66,7 @@ $json->attachment[] = array(
 if ( \get_the_author_meta( 'user_url', $author_id ) ) {
 	$json->attachment[] = array(
 		'type' => 'PropertyValue',
-		'name' => __( 'Website', 'activitypub' ),
+		'name' => \__( 'Website', 'activitypub' ),
 		'value' => \html_entity_decode(
 			'<a rel="me" title="' . \esc_attr( \get_the_author_meta( 'user_url', $author_id ) ) . '" target="_blank" href="' . \get_the_author_meta( 'user_url', $author_id ) . '">' . \wp_parse_url( \get_the_author_meta( 'user_url', $author_id ), \PHP_URL_HOST ) . '</a>',
 			\ENT_QUOTES,
diff --git a/templates/settings.php b/templates/settings.php
index 11c1eb4..099ab54 100644
--- a/templates/settings.php
+++ b/templates/settings.php
@@ -14,7 +14,7 @@
 			<tbody>
 				<tr>
 					<th scope="row">
-						<?php esc_html_e( 'Post-Content', 'activitypub' ); ?>
+						<?php \esc_html_e( 'Post-Content', 'activitypub' ); ?>
 					</th>
 					<td>
 						<p>
@@ -34,7 +34,7 @@
 					</th>
 					<td>
 						<p><label><input type="checkbox" name="activitypub_use_shortlink" id="activitypub_use_shortlink" value="1" <?php echo \checked( '1', \get_option( 'activitypub_use_shortlink', '0' ) ); ?> /> <?php \esc_html_e( 'Use the Shortlink instead of the permalink', 'activitypub' ); ?></label></p>
-						<p class="description"><?php \printf( esc_html( 'I can recommend %sHum%s, to prettify the Shortlinks', 'activitypub' ), '<a href="https://wordpress.org/plugins/hum/" target="_blank">', '</a>' ); ?></p>
+						<p class="description"><?php \printf( \esc_html( 'I can recommend %sHum%s, to prettify the Shortlinks', 'activitypub' ), '<a href="https://wordpress.org/plugins/hum/" target="_blank">', '</a>' ); ?></p>
 					</td>
 				</tr>
 				<tr>
@@ -121,6 +121,6 @@
 	</form>
 
 	<p>
-		<small><?php _e( 'If you like this plugin, what about a small <a href="https://notiz.blog/donate">donation</a>?', 'activitypub' ); ?></small>
+		<small><?php \_e( 'If you like this plugin, what about a small <a href="https://notiz.blog/donate">donation</a>?', 'activitypub' ); ?></small>
 	</p>
 </div>
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 9c550d9..cfc6d00 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -14,7 +14,7 @@ require_once $_tests_dir . '/includes/functions.php';
 function _manually_load_plugin() {
 	require \dirname( \dirname( __FILE__ ) ) . '/activitypub.php';
 }
-tests_add_filter( 'muplugins_loaded', '_manually_load_plugin' );
+\tests_add_filter( 'muplugins_loaded', '_manually_load_plugin' );
 
 require $_tests_dir . '/includes/bootstrap.php';
 
diff --git a/tests/test-class-activitypub-hashtag.php b/tests/test-class-activitypub-hashtag.php
index 54d622e..e7699d2 100644
--- a/tests/test-class-activitypub-hashtag.php
+++ b/tests/test-class-activitypub-hashtag.php
@@ -10,9 +10,9 @@ class Test_Activitypub_Hashtag extends WP_UnitTestCase {
 	}
 
 	public function the_content_provider() {
-		wp_create_term( 'object', 'post_tag' );
-		$object = get_term_by( 'name', 'object', 'post_tag' );
-		$link = get_term_link( $object, 'post_tag' );
+		\wp_create_term( 'object', 'post_tag' );
+		$object = \get_term_by( 'name', 'object', 'post_tag' );
+		$link = \get_term_link( $object, 'post_tag' );
 
 		return array(
 			array( 'test', 'test' ),
diff --git a/tests/test-class-activitypub.php b/tests/test-class-activitypub.php
index 090389b..26efbf6 100644
--- a/tests/test-class-activitypub.php
+++ b/tests/test-class-activitypub.php
@@ -1,10 +1,10 @@
 <?php
 class Test_Activitypub extends WP_UnitTestCase {
 	public function test_post_type_support() {
-		add_post_type_support( 'post', 'activitypub' );
-		add_post_type_support( 'page', 'activitypub' );
+		\add_post_type_support( 'post', 'activitypub' );
+		\add_post_type_support( 'page', 'activitypub' );
 
-		$this->assertContains( 'post', get_post_types_by_support( 'activitypub' ) );
-		$this->assertContains( 'page', get_post_types_by_support( 'activitypub' ) );
+		$this->assertContains( 'post', \get_post_types_by_support( 'activitypub' ) );
+		$this->assertContains( 'page', \get_post_types_by_support( 'activitypub' ) );
 	}
 }
diff --git a/tests/test-class-db-activitypub-followers.php b/tests/test-class-db-activitypub-followers.php
index 295bf24..c502bf2 100644
--- a/tests/test-class-db-activitypub-followers.php
+++ b/tests/test-class-db-activitypub-followers.php
@@ -7,7 +7,7 @@ class Test_Db_Activitypub_Followers extends WP_UnitTestCase {
 			'id' => 'http://sally.example.org',
 			'name' => 'Sally Smith',
 		);
-		update_user_meta( 1, 'activitypub_followers', $followers );
+		\update_user_meta( 1, 'activitypub_followers', $followers );
 
 		$db_followers = \Activitypub\Peer\Followers::get_followers( 1 );