diff --git a/boot.php b/boot.php
index cc916c600..e913dbc96 100755
--- a/boot.php
+++ b/boot.php
@@ -711,6 +711,7 @@ class App {
 	public static  $module;
 	public static  $pager;
 	public static  $strings;
+	public static  $stringsave;   // used in push_lang() and pop_lang()
 	public static  $hooks;
 	public static  $timezone;
 	public static  $interactive = true;
diff --git a/include/language.php b/include/language.php
index 1a012cb84..d6b7606ca 100644
--- a/include/language.php
+++ b/include/language.php
@@ -109,7 +109,7 @@ function pop_lang() {
 	if(App::$language === App::$langsave)
 		return;
 
-	if(isset(App::$stringsave))
+	if(isset(App::$stringsave) && is_array(App::$stringsave))
 		App::$strings = App::$stringsave;
 	else
 		App::$strings = array();