diff --git a/aqt/browser.py b/aqt/browser.py
index 8a2ff5088..9c8dbc418 100644
--- a/aqt/browser.py
+++ b/aqt/browser.py
@@ -778,7 +778,7 @@ by clicking on one on the left."""))
     def _modelTree(self, root):
         for m in sorted(self.col.models.all(), key=itemgetter("name")):
             mitem = self.CallbackItem(
-                m['name'], lambda m=m: self.setFilter("mid", m['id']))
+                m['name'], lambda m=m: self.setFilter("mid", str(m['id'])))
             mitem.setIcon(0, QIcon(":/icons/product_design.png"))
             root.addChild(mitem)
             # for t in m['tmpls']: