diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
index c00262c..7908bad 100644
--- a/system/libraries/Session/Session.php
+++ b/system/libraries/Session/Session.php
@@ -766,7 +766,7 @@
 	public function set_flashdata($data, $value = NULL)
 	{
 		$this->set_userdata($data, $value);
-		$this->mark_as_flash($data);
+		$this->mark_as_flash(is_array($data) ? array_keys($data) : $data);
 	}
 
 	// ------------------------------------------------------------------------