diff --git a/src/components/ItemsList.tsx b/src/components/ItemsList.tsx
index 3ef91c1..64de2e2 100644
--- a/src/components/ItemsList.tsx
+++ b/src/components/ItemsList.tsx
@@ -386,8 +386,15 @@ export function ItemsList({ url }: ItemsListProps) {
     console.log('Adding property:', property);
     const normalizedProperty = property.replace('http://www.wikidata.org/prop/', '');
     
-    if (!normalizedProperty || selectedProperties[normalizedProperty]) {
-      console.log('Property already exists or invalid:', normalizedProperty);
+    // Check if property is invalid,
+    if (!normalizedProperty) {
+      console.log('Property is invalid:', normalizedProperty);
+      return;
+    }
+
+    // Check if property is already in customProperties array (visible in UI)
+    if (customProperties.includes(normalizedProperty)) {
+      console.log('Property already visible in UI:', normalizedProperty);
       return;
     }