diff --git a/system/database/drivers/pdo/pdo_forge.php b/system/database/drivers/pdo/pdo_forge.php
index 8ce4513..5645750 100644
--- a/system/database/drivers/pdo/pdo_forge.php
+++ b/system/database/drivers/pdo/pdo_forge.php
@@ -112,8 +112,7 @@
 
 		if (count($primary_keys) > 0)
 		{
-			$primary_keys = $this->db->escape_identifiers($primary_keys);
-			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $primary_keys).')';
+			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->protect_identifiers($primary_keys)).')';
 		}
 
 		if (is_array($keys) && count($keys) > 0)
@@ -121,7 +120,7 @@
 			foreach ($keys as $key)
 			{
 				$key = is_array($key)
-					? $this->db->escape_identifiers($key)
+					? $this->db->protect_identifiers($key)
 					: array($this->db->escape_identifiers($key));
 
 				$sql .= ",\n\tFOREIGN KEY (".implode(', ', $key).')';