diff --git a/wp-admin/admin.php b/wp-admin/admin.php
index 2248be4969..11bd998be8 100644
--- a/wp-admin/admin.php
+++ b/wp-admin/admin.php
@@ -77,10 +77,15 @@ if (isset($plugin_page)) {
 		wp_die(__('Invalid importer.'));
 	}
 
-	if (! file_exists(ABSPATH . "wp-admin/import/$importer.php"))
-		wp_die(__('Cannot load importer.'));
-
-	include(ABSPATH . "wp-admin/import/$importer.php");
+	// Allow plugins to define importers as well
+	if (! function_exists($wp_importers[$importer][2]))
+	{
+		if (! file_exists(ABSPATH . "wp-admin/import/$importer.php"))
+		{
+			wp_die(__('Cannot load importer.'));
+		}
+		include(ABSPATH . "wp-admin/import/$importer.php");
+	}
 
 	$parent_file = 'edit.php';
 	$submenu_file = 'import.php';