--- a/svghmi/widgets_common.ysl2	Thu Feb 18 12:02:28 2021 +0100
+++ b/svghmi/widgets_common.ysl2	Fri Feb 19 10:03:00 2021 +0100
@@ -96,7 +96,7 @@
     ]);
     var persistent_indexes = new Map();
     var cache = hmitree_types.map(_ignored => undefined);
-    var updates = {};
+    var updates = new Map();
 
     function page_local_index(varname, pagename){
         let pagevars = hmi_locals[pagename];
@@ -116,7 +116,7 @@
         let defaultval = local_defaults[varname];
         if(defaultval != undefined) {
             cache[new_index] = defaultval; 
-            updates[new_index] = defaultval;
+            updates.set(new_index, defaultval);
             if(persistent_locals.has(varname))
                 persistent_indexes.set(new_index, varname);
         }