diff --git a/editor.planx.uk/src/pages/FlowEditor/lib/store/preview.ts b/editor.planx.uk/src/pages/FlowEditor/lib/store/preview.ts
index 3781ba2348..6c7c682d97 100644
--- a/editor.planx.uk/src/pages/FlowEditor/lib/store/preview.ts
+++ b/editor.planx.uk/src/pages/FlowEditor/lib/store/preview.ts
@@ -942,7 +942,7 @@ const collectedFlagValuesByCategory = (
     if (breadcrumb.answers) {
       breadcrumb.answers.forEach((answerId) => {
         const node = flow[answerId];
-        if (node.data?.flags) {
+        if (node?.data?.flags) {
           node.data.flags.forEach((flag: Flag["value"]) => {
             if (possibleFlagValues.includes(flag)) collectedFlags.push(flag);
           });