diff --git a/app/assets/javascripts/modules/mobile-filters-modal.js b/app/assets/javascripts/modules/mobile-filters-modal.js
index b93a6f7e1..1eea20775 100644
--- a/app/assets/javascripts/modules/mobile-filters-modal.js
+++ b/app/assets/javascripts/modules/mobile-filters-modal.js
@@ -97,10 +97,8 @@ window.GOVUK.Modules = window.GOVUK.Modules || {};
       type: 'finder',
       text: 'Filter',
       section: 'Filter',
-      index: {
-        index_section: 0,
-        index_section_count: indexSectionCount
-      }
+      index_section: 0,
+      index_section_count: indexSectionCount
     }))
   }
 
diff --git a/spec/javascripts/modules/mobile-filters-modal.spec.js b/spec/javascripts/modules/mobile-filters-modal.spec.js
index 42da78329..72fa767aa 100644
--- a/spec/javascripts/modules/mobile-filters-modal.spec.js
+++ b/spec/javascripts/modules/mobile-filters-modal.spec.js
@@ -142,10 +142,8 @@ describe('Mobile filters', function () {
           type: 'finder',
           text: 'Filter',
           section: 'Filter',
-          index: {
-            index_section: 0,
-            index_section_count: 5
-          }
+          index_section: 0,
+          index_section_count: 5
         }
         expect(button.getAttribute('data-ga4-event')).toEqual(JSON.stringify(expected))
       })