diff --git a/src/wp-admin/includes/class-wp-site-health.php b/src/wp-admin/includes/class-wp-site-health.php
index 19d109d447..afcbfcb6f9 100644
--- a/src/wp-admin/includes/class-wp-site-health.php
+++ b/src/wp-admin/includes/class-wp-site-health.php
@@ -1886,7 +1886,7 @@ class WP_Site_Health {
 		);
 
 		if ( ! function_exists( 'WP_Filesystem' ) ) {
-			require_once ABSPATH . '/wp-admin/includes/file.php';
+			require_once ABSPATH . 'wp-admin/includes/file.php';
 		}
 
 		ob_start();
diff --git a/src/wp-includes/class-wp-plugin-dependencies.php b/src/wp-includes/class-wp-plugin-dependencies.php
index 0850ffd2a2..e4dc4b0f40 100644
--- a/src/wp-includes/class-wp-plugin-dependencies.php
+++ b/src/wp-includes/class-wp-plugin-dependencies.php
@@ -159,7 +159,7 @@ class WP_Plugin_Dependencies {
 	 * @return bool Whether the plugin has active dependents.
 	 */
 	public static function has_active_dependents( $plugin_file ) {
-		require_once ABSPATH . '/wp-admin/includes/plugin.php';
+		require_once ABSPATH . 'wp-admin/includes/plugin.php';
 
 		$dependents = self::get_dependents( self::convert_to_slug( $plugin_file ) );
 		foreach ( $dependents as $dependent ) {
@@ -235,7 +235,7 @@ class WP_Plugin_Dependencies {
 			return false;
 		}
 
-		require_once ABSPATH . '/wp-admin/includes/plugin.php';
+		require_once ABSPATH . 'wp-admin/includes/plugin.php';
 
 		foreach ( self::$dependencies[ $plugin_file ] as $dependency ) {
 			$dependency_filepath = self::get_dependency_filepath( $dependency );
@@ -495,7 +495,7 @@ class WP_Plugin_Dependencies {
 			wp_send_json_success( $status );
 		}
 
-		require_once ABSPATH . '/wp-admin/includes/plugin.php';
+		require_once ABSPATH . 'wp-admin/includes/plugin.php';
 
 		$inactive_dependencies = array();
 		foreach ( $dependencies as $dependency ) {
@@ -544,7 +544,7 @@ class WP_Plugin_Dependencies {
 			return self::$plugins;
 		}
 
-		require_once ABSPATH . '/wp-admin/includes/plugin.php';
+		require_once ABSPATH . 'wp-admin/includes/plugin.php';
 		self::$plugins = get_plugins();
 
 		return self::$plugins;
diff --git a/src/wp-includes/update.php b/src/wp-includes/update.php
index 3e838e98fe..cac5aecab6 100644
--- a/src/wp-includes/update.php
+++ b/src/wp-includes/update.php
@@ -1121,7 +1121,7 @@ function _wp_delete_all_temp_backups() {
 	global $wp_filesystem;
 
 	if ( ! function_exists( 'WP_Filesystem' ) ) {
-		require_once ABSPATH . '/wp-admin/includes/file.php';
+		require_once ABSPATH . 'wp-admin/includes/file.php';
 	}
 
 	ob_start();