diff --git a/phpBB/includes/search/fulltext_mysql.php b/phpBB/includes/search/fulltext_mysql.php
index c72e674011..da3833754e 100644
--- a/phpBB/includes/search/fulltext_mysql.php
+++ b/phpBB/includes/search/fulltext_mysql.php
@@ -473,7 +473,7 @@ class fulltext_mysql extends search_backend
 
 		while ($row = $db->sql_fetchrow($result))
 		{
-			$id_ary[] = $row[$field];
+			$id_ary[] = (int) $row[$field];
 		}
 		$db->sql_freeresult($result);
 
@@ -650,7 +650,7 @@ class fulltext_mysql extends search_backend
 
 		while ($row = $db->sql_fetchrow($result))
 		{
-			$id_ary[] = $row[$field];
+			$id_ary[] = (int) $row[$field];
 		}
 		$db->sql_freeresult($result);
 
diff --git a/phpBB/includes/search/fulltext_native.php b/phpBB/includes/search/fulltext_native.php
index e1ab02ba9d..c89e92711e 100644
--- a/phpBB/includes/search/fulltext_native.php
+++ b/phpBB/includes/search/fulltext_native.php
@@ -744,7 +744,7 @@ class fulltext_native extends search_backend
 
 		while ($row = $db->sql_fetchrow($result))
 		{
-			$id_ary[] = $row[(($type == 'posts') ? 'post_id' : 'topic_id')];
+			$id_ary[] = (int) $row[(($type == 'posts') ? 'post_id' : 'topic_id')];
 		}
 		$db->sql_freeresult($result);
 
@@ -986,7 +986,7 @@ class fulltext_native extends search_backend
 
 		while ($row = $db->sql_fetchrow($result))
 		{
-			$id_ary[] = $row[$field];
+			$id_ary[] = (int) $row[$field];
 		}
 		$db->sql_freeresult($result);