diff --git a/strange_eons_to_arkhamdb.js b/strange_eons_to_arkhamdb.js
index ed8ab31..d07015e 100644
--- a/strange_eons_to_arkhamdb.js
+++ b/strange_eons_to_arkhamdb.js
@@ -145,7 +145,7 @@ function build_card(component) {
 
   var subtitle = component.settings.get('Subtitle');
   if (subtitle && subtitle != '') {
-    card_data.subname = subtitle;
+    card_data.subname = String(subtitle);
   }
 
   var faction2 = component.settings.get('CardClass2');