diff --git a/phpBB/phpbb/auth/auth.php b/phpBB/phpbb/auth/auth.php
index 2ca2d374bd..7777796736 100644
--- a/phpBB/phpbb/auth/auth.php
+++ b/phpBB/phpbb/auth/auth.php
@@ -772,7 +772,7 @@ class auth
 
 		$sql_group = ($group_id !== false) ? ((!is_array($group_id)) ? 'group_id = ' . (int) $group_id : $db->sql_in_set('group_id', array_map('intval', $group_id))) : '';
 		$sql_forum = ($forum_id !== false) ? ((!is_array($forum_id)) ? 'AND a.forum_id = ' . (int) $forum_id : 'AND ' . $db->sql_in_set('a.forum_id', array_map('intval', $forum_id))) : '';
-		$sql_is_local = $forum_id !== false ? 'AND ao.is_local <> 0' : '';
+		$sql_is_local = !empty($forum_id) ? 'AND ao.is_local <> 0' : '';
 
 		$sql_opts = '';
 		$hold_ary = $sql_ary = array();
diff --git a/tests/functional/acp_permissions_test.php b/tests/functional/acp_permissions_test.php
index 92980dbfd7..fbcfa1ab24 100644
--- a/tests/functional/acp_permissions_test.php
+++ b/tests/functional/acp_permissions_test.php
@@ -149,4 +149,26 @@ class phpbb_functional_acp_permissions_test extends phpbb_functional_test_case
 		$this->assertContainsLang('ACL_M_EDIT', $page_text);
 		$this->assertContainsLang('ACL_M_MOVE', $page_text);
 	}
+
+	public function test_tracing_user_based_permissions()
+	{
+		$this->create_user('newlyregistereduser');
+
+		// Open user-based permissions masks page
+		$crawler = self::request('GET', "adm/index.php?i=acp_permissions&icat=16&mode=view_user_global&sid=" . $this->sid);
+
+		// Select newlyregistereduser
+		$form = $crawler->filter('#add_user')->form(['username' => ['newlyregistereduser']]);
+		$crawler = self::submit($form);
+
+		// Test 1st "Yes" permission tracing result match
+		$trace_link_yes = $crawler->filter('td.yes')->eq(0)->parents()->eq(0)->filter('a.trace')->link();
+		$crawler_trace_yes = self::$client->click($trace_link_yes);
+		$this->assertEquals(1, $crawler_trace_yes->filter('tr.row2 > td.yes')->count());
+
+		// Test 1st "Never" permission tracing result match
+		$trace_link_never = $crawler->filter('td.never')->eq(0)->parents()->eq(0)->filter('a.trace')->link();
+		$crawler_trace_never = self::$client->click($trace_link_never);
+		$this->assertEquals(1, $crawler_trace_never->filter('tr.row2 > td.never')->count());
+	}
 }