diff --git a/plugin.rb b/plugin.rb
index bd7f2e85..15f8d4ba 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -152,7 +152,9 @@ class SiteSettings::TypeSupervisor
   require_dependency 'topic'
   class ::Topic
     def has_event?
-      self.custom_fields['event_start']&.nonzero?
+      self.custom_fields['event_start'].present? &&
+      self.custom_fields['event_start'].is_a?(Numeric) &&
+      self.custom_fields['event_start'] != 0
     end
 
     def event