diff --git a/composer.json b/composer.json
index 9e113b8..d3c24fb 100644
--- a/composer.json
+++ b/composer.json
@@ -30,7 +30,7 @@
     },
     "autoload": {
         "psr-4": {
-            "Geniem\\Oopi\\": ["src/", "plugin.php"]
+            "Geniem\\Oopi\\": "src/"
         }
     },
     "require-dev": {
diff --git a/plugin.php b/plugin.php
index c121569..7f34aec 100644
--- a/plugin.php
+++ b/plugin.php
@@ -12,19 +12,6 @@
 
 namespace Geniem\Oopi;
 
-use Geniem\Oopi\Exception\TypeException;
-use Geniem\Oopi\Importable\AttachmentImportable;
-use Geniem\Oopi\Importable\PostImportable;
-use Geniem\Oopi\Importable\TermImportable;
-use Geniem\Oopi\Importer\AttachmentImporter;
-use Geniem\Oopi\Importer\PostImporter;
-use Geniem\Oopi\Importer\TermImporter;
-use Geniem\Oopi\Interfaces\Importable;
-use Geniem\Oopi\Interfaces\Importer;
-use Geniem\Oopi\Localization\LanguageUtil;
-use ReflectionClass;
-use ReflectionException;
-
 if ( ! defined( 'ABSPATH' ) ) {
     exit;
 }
@@ -34,127 +21,6 @@
     require_once __DIR__ . '/vendor/autoload.php';
 }
 
-/**
- * The base class for the plugin.
- *
- * @package Geniem
- */
-class Plugin {
-
-    /**
-     * Holds the general plugin data.
-     *
-     * @var array
-     */
-    protected static $plugin_data = [
-        'TABLE_NAME' => 'oopi_log',
-    ];
-
-    /**
-     * Run tasks when plugin is activated.
-     */
-    public static function install() {
-        // Install log handler.
-        Log::install();
-
-        // Register cron jobs.
-        CronJobs::install();
-    }
-
-
-    /**
-     * Run tasks when plugin is deactivated.
-     */
-    public static function uninstall() {
-        // Remove cron jobs.
-        CronJobs::uninstall();
-    }
-
-    /**
-     * A map of importable class names and their corresponding import handlers.
-     *
-     * @var Importable[]
-     */
-    private static $importables = [];
-
-    /**
-     * Initialize the plugin.
-     */
-    public static function init() {
-        // Set the plugin version.
-        $plugin_data       = get_file_data( __FILE__, [ 'Version' => 'Version' ], 'plugin' );
-        self::$plugin_data = array_merge( $plugin_data, self::$plugin_data );
-
-        // Set the basic settings.
-        Settings::init( self::$plugin_data );
-
-        // Initialize the import handlers for importables.
-        self::set_initial_import_handlers();
-
-        // Register the cron job hooks.
-        CronJobs::init();
-
-        // Initialize plugin controllers after plugins are loaded.
-        add_action( 'wp_loaded', function() {
-            LanguageUtil::init();
-        } );
-    }
-
-    /**
-     * Sets the initial state of global handlers for all importables.
-     */
-    protected static function set_initial_import_handlers() {
-        static::$importables = [
-            PostImportable::class       => PostImporter::class,
-            TermImportable::class       => TermImporter::class,
-            AttachmentImportable::class => AttachmentImporter::class,
-        ];
-    }
-
-    /**
-     * Add or override a global importable and/or its import handler.
-     *
-     * @param string $importable_class The importable class name.
-     * @param string $importer_class   The importer class name.
-     *
-     * @throws ReflectionException|TypeException If any of the given classes are missing or they are of the wrong type,
-     *                                           an error is thrown.
-     */
-    public static function set_importable( string $importable_class, string $importer_class ) {
-        $importable_reflect = new ReflectionClass( $importable_class );
-        $importer_reflect   = new ReflectionClass( $importer_class );
-
-        $importable_interface = Importable::class;
-        $importer_interface   = Importer::class;
-
-        $valid_classes =
-            $importable_reflect->implementsInterface( Importable::class )
-            && $importer_reflect->implementsInterface( Importer::class );
-
-        if ( $valid_classes ) {
-            static::$importables[ $importable_class ] = $importer_class;
-        }
-        else {
-            throw new TypeException(
-                "The passed classes must implement the following interfaces: 
-                importable: $importable_interface, importer: $importer_interface."
-            );
-        }
-    }
-
-    /**
-     * Get the global importer for the given importable class name.
-     *
-     * @param string $importable_class The importable class name.
-     *
-     * @return ?Importer
-     */
-    public static function get_importer( string $importable_class ) : ?Importer {
-        $importer = new static::$importables[ $importable_class ]();
-        return $importer;
-    }
-}
-
 // Initialize the plugin.
 Plugin::init();
 
diff --git a/src/Plugin.php b/src/Plugin.php
new file mode 100644
index 0000000..1635cad
--- /dev/null
+++ b/src/Plugin.php
@@ -0,0 +1,140 @@
+<?php
+/**
+ * The main plugin class.
+ */
+
+namespace Geniem\Oopi;
+
+use Geniem\Oopi\Exception\TypeException;
+use Geniem\Oopi\Importable\AttachmentImportable;
+use Geniem\Oopi\Importable\PostImportable;
+use Geniem\Oopi\Importable\TermImportable;
+use Geniem\Oopi\Importer\AttachmentImporter;
+use Geniem\Oopi\Importer\PostImporter;
+use Geniem\Oopi\Importer\TermImporter;
+use Geniem\Oopi\Interfaces\Importable;
+use Geniem\Oopi\Interfaces\Importer;
+use Geniem\Oopi\Localization\LanguageUtil;
+use ReflectionClass;
+use ReflectionException;
+
+/**
+ * The base class for the plugin.
+ *
+ * @package Geniem
+ */
+class Plugin {
+
+    /**
+     * Holds the general plugin data.
+     *
+     * @var array
+     */
+    protected static $plugin_data = [
+        'TABLE_NAME' => 'oopi_log',
+    ];
+
+    /**
+     * Run tasks when plugin is activated.
+     */
+    public static function install() {
+        // Install log handler.
+        Log::install();
+
+        // Register cron jobs.
+        CronJobs::install();
+    }
+
+
+    /**
+     * Run tasks when plugin is deactivated.
+     */
+    public static function uninstall() {
+        // Remove cron jobs.
+        CronJobs::uninstall();
+    }
+
+    /**
+     * A map of importable class names and their corresponding import handlers.
+     *
+     * @var Importable[]
+     */
+    private static $importables = [];
+
+    /**
+     * Initialize the plugin.
+     */
+    public static function init() {
+        // Set the plugin version.
+        $plugin_data       = get_file_data( dirname( __DIR__ ) . '/plugin.php', [ 'Version' => 'Version' ], 'plugin' );
+        self::$plugin_data = array_merge( $plugin_data, self::$plugin_data );
+
+        // Set the basic settings.
+        Settings::init( self::$plugin_data );
+
+        // Initialize the import handlers for importables.
+        self::set_initial_import_handlers();
+
+        // Register the cron job hooks.
+        CronJobs::init();
+
+        // Initialize plugin controllers after plugins are loaded.
+        add_action( 'wp_loaded', function() {
+            LanguageUtil::init();
+        } );
+    }
+
+    /**
+     * Sets the initial state of global handlers for all importables.
+     */
+    protected static function set_initial_import_handlers() {
+        static::$importables = [
+            PostImportable::class       => PostImporter::class,
+            TermImportable::class       => TermImporter::class,
+            AttachmentImportable::class => AttachmentImporter::class,
+        ];
+    }
+
+    /**
+     * Add or override a global importable and/or its import handler.
+     *
+     * @param string $importable_class The importable class name.
+     * @param string $importer_class   The importer class name.
+     *
+     * @throws ReflectionException|TypeException If any of the given classes are missing or they are of the wrong type,
+     *                                           an error is thrown.
+     */
+    public static function set_importable( string $importable_class, string $importer_class ) {
+        $importable_reflect = new ReflectionClass( $importable_class );
+        $importer_reflect   = new ReflectionClass( $importer_class );
+
+        $importable_interface = Importable::class;
+        $importer_interface   = Importer::class;
+
+        $valid_classes =
+            $importable_reflect->implementsInterface( Importable::class )
+            && $importer_reflect->implementsInterface( Importer::class );
+
+        if ( $valid_classes ) {
+            static::$importables[ $importable_class ] = $importer_class;
+        }
+        else {
+            throw new TypeException(
+                "The passed classes must implement the following interfaces: 
+                importable: $importable_interface, importer: $importer_interface."
+            );
+        }
+    }
+
+    /**
+     * Get the global importer for the given importable class name.
+     *
+     * @param string $importable_class The importable class name.
+     *
+     * @return ?Importer
+     */
+    public static function get_importer( string $importable_class ) : ?Importer {
+        $importer = new static::$importables[ $importable_class ]();
+        return $importer;
+    }
+}
diff --git a/src/Util.php b/src/Util.php
index 00f7ce1..d3cbff2 100644
--- a/src/Util.php
+++ b/src/Util.php
@@ -5,7 +5,9 @@
 
 namespace Geniem\Oopi;
 
-use Geniem\Oopi\Interfaces\ErrorHandler;/**
+use Geniem\Oopi\Interfaces\ErrorHandler;
+
+/**
  * Class Util
  * A collection of utility functions.
  *