diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index c284d7d..2b9fb16 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -239,7 +239,7 @@
 			show_error('Key information is required for that operation.');
 		}
 
-		if (is_array($key))
+		if ($primary === TRUE && is_array($key))
 		{
 			foreach ($key as $one)
 			{