diff --git a/.psalm/autoloader.php b/.psalm/autoloader.php
index 5474b0b..3592d19 100644
--- a/.psalm/autoloader.php
+++ b/.psalm/autoloader.php
@@ -3,7 +3,7 @@
     return;
 }
 
-define('ABSPATH', './vendor/roots/wordpress/');
+define('ABSPATH', './vendor/johnpbloch/wordpress-core/');
 define('WPINC', 'wp-includes');
 define('WP_CONTENT_DIR', ABSPATH . 'wp-content');
 
diff --git a/composer.json b/composer.json
index 1667e23..1d6c84d 100644
--- a/composer.json
+++ b/composer.json
@@ -22,10 +22,10 @@
     "require-dev": {
         "phpunit/phpunit": "~7.5.20 || ^8",
         "inpsyde/php-coding-standards": "^1",
-        "vimeo/psalm": "^3.14.2",
+        "vimeo/psalm": "@stable",
         "mockery/mockery": "~1.3.3",
         "brain/monkey": "^2.4.2",
-        "roots/wordpress": "^5.5.1"
+        "johnpbloch/wordpress-core": "@stable"
     },
     "autoload": {
         "psr-4": {
@@ -55,7 +55,6 @@
     "extra": {
         "branch-alias": {
             "dev-master": "1.x-dev"
-        },
-        "wordpress-install-dir": "vendor/roots/wordpress"
+        }
     }
 }
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index ba9d37e..6708883 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -2,10 +2,20 @@
 <ruleset>
 
     <file>./src/</file>
+    <file>./tests/</file>
 
     <arg value="sp"/>
     <arg name="colors"/>
-    <config name="testVersion" value="7.2-"/>
+    <config name="testVersion" value="7.1-"/>
 
     <rule ref="Inpsyde"/>
+
+    <rule ref="Inpsyde.CodeQuality.Psr4">
+        <properties>
+            <property
+                name="psr4"
+                type="array"
+                value="Inpsyde=>src,Inpsyde\Tests=>tests"/>
+        </properties>
+    </rule>
 </ruleset>
diff --git a/psalm.xml b/psalm.xml
index fb1ed5c..3469222 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -21,5 +21,6 @@
 
    <issueHandlers>
         <MixedAssignment errorLevel="suppress" />
+        <RedundantCastGivenDocblockType errorLevel="suppress" />
     </issueHandlers>
 </psalm>
diff --git a/src/WpContext.php b/src/WpContext.php
index d1c764a..6558aa5 100644
--- a/src/WpContext.php
+++ b/src/WpContext.php
@@ -45,7 +45,7 @@ final class WpContext implements \JsonSerializable
      */
     public static function new(): WpContext
     {
-        return new static(array_fill_keys(self::ALL, false));
+        return new self(array_fill_keys(self::ALL, false));
     }
 
     /**
@@ -70,9 +70,11 @@ public static function determine(): WpContext
         // When nothing else matches, we assume it is a front-office request.
         $isFront = $undetermined && !$isRest && !$isLogin;
 
-        // Note that when core is installing **only** `INSTALLING` will be true, not even `CORE`.
-        // This is done to do as less as possible during installation, when most of WP does not act
-        // as expected.
+        /*
+         * Note that when core is installing **only** `INSTALLING` will be true, not even `CORE`.
+         * This is done to do as less as possible during installation, when most of WP does not act
+         * as expected.
+         */
 
         $instance = new self(
             [
@@ -107,9 +109,11 @@ private static function isRestRequest(): bool
             return !empty($_GET['rest_route']); // phpcs:ignore
         }
 
-        // This is needed because, if called early, global $wp_rewrite is not defined but required
-        // by get_rest_url(). WP will reuse what we set here, or in worst case will replace, but no
-        // consequences for us in any case.
+        /*
+         * This is needed because, if called early, global $wp_rewrite is not defined but required
+         * by get_rest_url(). WP will reuse what we set here, or in worst case will replace, but no
+         * consequences for us in any case.
+         */
         if (empty($GLOBALS['wp_rewrite'])) {
             $GLOBALS['wp_rewrite'] = new \WP_Rewrite();
         }
@@ -282,7 +286,7 @@ public function isInstalling(): bool
     /**
      * @return array
      */
-    public function jsonSerialize()
+    public function jsonSerialize(): array
     {
         return $this->data;
     }
@@ -328,6 +332,7 @@ private function removeActionHooks(): void
         foreach ($this->actionCallbacks as $action => $callback) {
             remove_action($action, $callback, PHP_INT_MIN);
         }
+        $this->actionCallbacks = [];
     }
 
     /**
@@ -341,5 +346,7 @@ private function resetAndForce(string $context): void
         $this->data[self::CORE] = true;
         $this->data[self::CLI] = $cli;
         $this->data[$context] = true;
+
+        $this->removeActionHooks();
     }
 }
diff --git a/tests/WpContextTest.php b/tests/WpContextTest.php
index 6e4da7d..d799ee9 100644
--- a/tests/WpContextTest.php
+++ b/tests/WpContextTest.php
@@ -1,4 +1,4 @@
-<?php # -*- coding: utf-8 -*-
+<?php
 
 declare(strict_types=1);
 
@@ -28,9 +28,11 @@ protected function setUp(): void
     {
         parent::setUp();
         Monkey\setUp();
-        Monkey\Functions\expect('add_query_arg')->with([])->andReturnUsing(function (): string {
-            return $this->currentPath;
-        });
+        Monkey\Functions\expect('add_query_arg')
+            ->with([])
+            ->andReturnUsing(function (): string {
+                return $this->currentPath;
+            });
     }
 
     /**
@@ -105,7 +107,7 @@ public function testIsLoginLate(): void
 
         $onLoginInit = null;
         Monkey\Actions\expectAdded('login_init')
-            ->whenHappen(function (callable $callback) use (&$onLoginInit) {
+            ->whenHappen(static function (callable $callback) use (&$onLoginInit) {
                 $onLoginInit = $callback;
             });
 
@@ -161,7 +163,7 @@ public function testIsRestLate(): void
 
         $onRestInit = null;
         Monkey\Actions\expectAdded('rest_api_init')
-            ->whenHappen(function (callable $callback) use (&$onRestInit) {
+            ->whenHappen(static function (callable $callback) use (&$onRestInit) {
                 $onRestInit = $callback;
             });
 
@@ -364,8 +366,9 @@ private function mockIsLoginRequest(bool $is): void
     {
         $is and $this->currentPath = '/wp-login.php';
         Monkey\Functions\when('wp_login_url')->justReturn('https://example.com/wp-login.php');
-        Monkey\Functions\when('home_url')->alias(static function (string $path = ''): string {
-            return 'https://example.com/' . ltrim($path, '/');
-        });
+        Monkey\Functions\when('home_url')
+            ->alias(static function (string $path = ''): string {
+                return 'https://example.com/' . ltrim($path, '/');
+            });
     }
 }