diff --git a/packages/core-compat-api/src/convertLegacyRouteRef.ts b/packages/core-compat-api/src/convertLegacyRouteRef.ts
index e6a52932ce..a5375e0692 100644
--- a/packages/core-compat-api/src/convertLegacyRouteRef.ts
+++ b/packages/core-compat-api/src/convertLegacyRouteRef.ts
@@ -200,7 +200,8 @@ export function convertLegacyRouteRef(
         return legacyRefStr;
       },
       getDefaultTarget() {
-        return newRef.getDefaultTarget();
+        // TODO(freben): These are not yet supported in the old system; just returning undefined for now
+        return undefined;
       },
       setId(id: string) {
         newRef.setId(id);