diff --git a/wagtail/admin/templatetags/wagtailadmin_tags.py b/wagtail/admin/templatetags/wagtailadmin_tags.py
index 03f97bcef..8af9ccd35 100644
--- a/wagtail/admin/templatetags/wagtailadmin_tags.py
+++ b/wagtail/admin/templatetags/wagtailadmin_tags.py
@@ -281,7 +281,7 @@ def querystring(context, **kwargs):
             querydict.pop(key, None)
         else:
             # Set the key otherwise
-            querydict[key] = value
+            querydict[key] = str(value)
 
     return '?' + querydict.urlencode()