diff --git a/changelog b/changelog
index 14e141cd788..ae9d525fc37 100644
--- a/changelog
+++ b/changelog
@@ -3,6 +3,8 @@ Version 1.7.2+svn:
     * New unit graphics and animations for the Troll Hero.
  * Language and i18n:
    * Updated translations: Dutch, French
+ * WML Engine:
+   * return 0 for length of arrays inside nonexistent containers (bug #13734)
  * Miscellaneous and bugfixes:
    * 'Recruit' and 'recall' don't appear in context menus unless the
      leader is on a keep. (bug #13856 and #13855)
diff --git a/src/gamestatus.cpp b/src/gamestatus.cpp
index 914a9556872..32f842f08c9 100644
--- a/src/gamestatus.cpp
+++ b/src/gamestatus.cpp
@@ -532,7 +532,14 @@ t_string& game_state::get_variable(const std::string& key)
 const t_string& game_state::get_variable_const(const std::string& key) const
 {
 	variable_info to_get(key, false, variable_info::TYPE_SCALAR);
-	if(!to_get.is_valid) return temporaries[key];
+	if(!to_get.is_valid) {
+			t_string& to_return = temporaries[key];
+			if(key.size() > 7 and key.substr(key.size()-7)==".length") {
+				// length is a special attribute, so guarantee its correctness
+				to_return = "0";
+			}
+			return to_return;
+	}
 	return to_get.as_scalar();
 }