--- a/svghmi/svghmi.js	Mon Oct 28 10:30:20 2019 +0100
+++ b/svghmi/svghmi.js	Mon Oct 28 19:52:43 2019 +0100
@@ -188,13 +188,16 @@
             subscribers[index].delete(widget);
         }
     }
-    /* add new subsribers if any */
-    if(new_desc) for(let widget of new_desc.widgets){
-        for(let index of widget.indexes){
-            subscribers[index].add(widget);
-        }
-    }
-
+
+    if(new_desc) {
+        /* add new subsribers if any */
+        for(let widget of new_desc.widgets){
+            for(let index of widget.indexes){
+                subscribers[index].add(widget);
+            }
+        }
+        svg_root.setAttribute('viewBox',new_desc.bbox.join(" "));
+    }
     current_page = page_name;
 
     update_subscriptions();