diff --git a/webapp/src/ClimateChart.ts b/webapp/src/ClimateChart.ts
index 7675eca..065fdcc 100644
--- a/webapp/src/ClimateChart.ts
+++ b/webapp/src/ClimateChart.ts
@@ -46,7 +46,7 @@ class ClimateChart {
 
     private async getInitialDataBlob(): Promise<SnapshotRecords> {
         try {
-            const data = await fetch(this.rootUrl + "/data?since" + (new Date().getTime() - this.minutesDisplayed * 60 * 1000));
+            const data = await fetch(this.rootUrl + "/data?since=" + (new Date().getTime() - this.minutesDisplayed * 60 * 1000));
             return await data.json();
         }
         catch (e) {