diff --git a/phpBB/includes/db/mysql4.php b/phpBB/includes/db/mysql4.php
index 3df2c0ad0d..143996a028 100644
--- a/phpBB/includes/db/mysql4.php
+++ b/phpBB/includes/db/mysql4.php
@@ -151,7 +151,7 @@ class dbal_mysql4 extends dbal
 			if ($total == 0)
 			{
 				// Because MySQL 4.1+ no longer supports -1 in LIMIT queries we set it to the maximum value
-				$total = 18446744073709551615;
+				$total = '18446744073709551615';
 			}
 
 			$query .= "\n LIMIT " . ((!empty($offset)) ? $offset . ', ' . $total : $total);
diff --git a/phpBB/includes/db/mysqli.php b/phpBB/includes/db/mysqli.php
index 82ee6ecf21..201d6af1e7 100644
--- a/phpBB/includes/db/mysqli.php
+++ b/phpBB/includes/db/mysqli.php
@@ -147,7 +147,7 @@ class dbal_mysqli extends dbal
 			if ($total == 0)
 			{
 				// MySQL 4.1+ no longer supports -1 in limit queries
-				$total = 18446744073709551615;
+				$total = '18446744073709551615';
 			}
 
 			$query .= "\n LIMIT " . ((!empty($offset)) ? $offset . ', ' . $total : $total);