diff --git a/src/admin/class-admin.php b/src/admin/class-admin.php
index 49ec24f..e81fdcd 100644
--- a/src/admin/class-admin.php
+++ b/src/admin/class-admin.php
@@ -90,14 +90,14 @@ class Admin {
 		/**
 		 * The class responsible for WYSIWYG editor integration.
 		 */
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'admin/class-wysiwyg.php';
+		require_once plugin_dir_path( __DIR__ ) . 'admin/class-wysiwyg.php';
 
 		$this->wysiwyg = new WYSIWYG( $this->plugin_name );
 
 		/**
 		 * The class responsible for constructing the plugin dashboard page(s).
 		 */
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'admin/layout/class-init.php';
+		require_once plugin_dir_path( __DIR__ ) . 'admin/layout/class-init.php';
 
 		new layout\Init( $this->plugin_name );
 	}
diff --git a/src/admin/layout/class-engine.php b/src/admin/layout/class-engine.php
index c03d6e1..ec6dff2 100644
--- a/src/admin/layout/class-engine.php
+++ b/src/admin/layout/class-engine.php
@@ -19,7 +19,7 @@ namespace footnotes\admin\layout;
 
 use footnotes\includes as Includes;
 
-require_once plugin_dir_path( dirname( __FILE__ ) ) . 'layout/class-init.php';
+require_once plugin_dir_path( __DIR__ ) . 'layout/class-init.php';
 
 /**
  * Class to be extended by page layout sub-classes.
diff --git a/src/admin/layout/class-init.php b/src/admin/layout/class-init.php
index 5d8afb4..00a2b89 100644
--- a/src/admin/layout/class-init.php
+++ b/src/admin/layout/class-init.php
@@ -125,7 +125,7 @@ class Init {
 		/**
 		 * Represents the plugin settings dashboard page.
 		 */
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'layout/class-settings.php';
+		require_once plugin_dir_path( __DIR__ ) . 'layout/class-settings.php';
 	}
 
 	/**
diff --git a/src/admin/layout/class-settings.php b/src/admin/layout/class-settings.php
index 53ec42d..64f0010 100644
--- a/src/admin/layout/class-settings.php
+++ b/src/admin/layout/class-settings.php
@@ -23,7 +23,7 @@ use footnotes\general as General;
 /**
  * Provides the abstract class to be extended for page layouts.
  */
-require_once plugin_dir_path( dirname( __FILE__ ) ) . 'layout/class-engine.php';
+require_once plugin_dir_path( __DIR__ ) . 'layout/class-engine.php';
 
 /**
  * Class to initialise all defined page layouts.
diff --git a/src/includes/class-core.php b/src/includes/class-core.php
index 69a02a9..95f91d1 100644
--- a/src/includes/class-core.php
+++ b/src/includes/class-core.php
@@ -124,32 +124,32 @@ class Core {
 		 * The class responsible for orchestrating the actions and filters of the
 		 * core plugin.
 		 */
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-loader.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-loader.php';
 
 		/**
 		 * The class responsible for defining internationalization functionality
 		 * of the plugin.
 		 */
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-i18n.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-i18n.php';
 
 		/**
 		 * The various utility classes.
 		 */
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-config.php';
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-convert.php';
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-settings.php';
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-template.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-config.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-convert.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-settings.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-template.php';
 
 		/**
 		 * The class responsible for defining all actions that occur in the admin area.
 		 */
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'admin/class-admin.php';
+		require_once plugin_dir_path( __DIR__ ) . 'admin/class-admin.php';
 
 		/**
 		 * The class responsible for defining all actions that occur in the public-facing
 		 * side of the site.
 		 */
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'public/class-general.php';
+		require_once plugin_dir_path( __DIR__ ) . 'public/class-general.php';
 
 		$this->loader = new Loader();
 
diff --git a/src/includes/class-i18n.php b/src/includes/class-i18n.php
index 626596b..af4275a 100644
--- a/src/includes/class-i18n.php
+++ b/src/includes/class-i18n.php
@@ -12,7 +12,7 @@ declare(strict_types=1);
 
 namespace footnotes\includes;
 
-require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-config.php';
+require_once plugin_dir_path( __DIR__ ) . 'includes/class-config.php';
 
 /**
  * Class providing internationalization functionality.
diff --git a/src/includes/class-settings.php b/src/includes/class-settings.php
index 7a279fd..46fd25e 100644
--- a/src/includes/class-settings.php
+++ b/src/includes/class-settings.php
@@ -17,7 +17,7 @@ namespace footnotes\includes;
  *
  * @todo Move to {@see Loader}.
  */
-require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-convert.php';
+require_once plugin_dir_path( __DIR__ ) . 'includes/class-convert.php';
 
 /**
  * Class defining configurable plugin settings.
diff --git a/src/includes/class-template.php b/src/includes/class-template.php
index a05d810..bcba85c 100644
--- a/src/includes/class-template.php
+++ b/src/includes/class-template.php
@@ -91,7 +91,7 @@ class Template {
 			return;
 		}
 
-		$this->plugin_directory = plugin_dir_path( dirname( __FILE__ ) );
+		$this->plugin_directory = plugin_dir_path( __DIR__ );
 
 		$template = $this->get_template( $p_str_file_type, $p_str_file_name, $p_str_extension );
 		if ( $template ) {
diff --git a/src/public/class-parser.php b/src/public/class-parser.php
index 194a4e7..3a536aa 100644
--- a/src/public/class-parser.php
+++ b/src/public/class-parser.php
@@ -268,10 +268,10 @@ class Parser {
 	 */
 	public function __construct() {
 		// TODO: Reorg dependencies.
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-config.php';
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-convert.php';
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-settings.php';
-		require_once plugin_dir_path( dirname( __FILE__ ) ) . 'includes/class-template.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-config.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-convert.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-settings.php';
+		require_once plugin_dir_path( __DIR__ ) . 'includes/class-template.php';
 
 		// TODO: Move to `General`.
 		$this->register_hooks();