diff --git a/templates/results.html b/templates/results.html
index 4c37e33..92642d0 100644
--- a/templates/results.html
+++ b/templates/results.html
@@ -264,8 +264,7 @@
 </p>
 
 <script>
-var stationCrs = {{ station_crs | tojson }};
-var travelDate = {{ travel_date | tojson }};
+var advanceFaresUrl = {{ url_for('api_advance_fares', station_crs=station_crs, travel_date=travel_date) | tojson }};
 var cachedAdvanceFares = {{ cached_advance_fares | tojson }};
 
 function updatePrices() {
@@ -315,7 +314,7 @@ function loadAdvanceFares() {
   btn.disabled = true;
   btn.textContent = 'Loading\u2026';
 
-  fetch('/api/advance_fares/' + stationCrs + '/' + travelDate)
+  fetch(advanceFaresUrl)
     .then(function(r) { return r.json(); })
     .then(function(data) {
       if (data.error) {