diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index 152f8f6..4d23e4e 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -348,7 +348,10 @@
 
 		if (($result = $this->db->query($sql)) !== FALSE)
 		{
-			isset($this->db->data_cache['table_names']) && $this->db->data_cache['table_names'][] = $table;
+			if (isset($this->db->data_cache['table_names']))
+			{
+				$this->db->data_cache['table_names'][] = $table;
+			}
 
 			// Most databases don't support creating indexes from within the CREATE TABLE statement
 			if ( ! empty($this->keys))