diff --git a/common/utils/array.ts b/common/utils/array.ts
index 37e88405..dbda549c 100644
--- a/common/utils/array.ts
+++ b/common/utils/array.ts
@@ -1,7 +1,7 @@
 export const indexByProperty = <T extends { [key: string]: any }>(
   array: T[],
   property: keyof T
-) => {
+): Record<string, T | undefined> => {
   const res: Record<string, T> = {};
   array.forEach((el) => {
     res[el[property]] = el;
diff --git a/modules/service/ServiceGraph.tsx b/modules/service/ServiceGraph.tsx
index ca8c0f2a..b096c004 100644
--- a/modules/service/ServiceGraph.tsx
+++ b/modules/service/ServiceGraph.tsx
@@ -53,9 +53,9 @@ export const ServiceGraph: React.FC<ServiceGraphProps> = (props: ServiceGraphPro
       data: allDates.map((date) => {
         const scheduledToday = scheduledDataByDate[date];
         const deliveredToday = deliveredDataByDate[date];
-        const anyDeliveredToday = deliveredToday?.miles_covered > 0;
+        const anyDeliveredToday = deliveredToday && deliveredToday.miles_covered > 0;
         const value =
-          scheduledToday.count && anyDeliveredToday ? Math.round(scheduledToday.count) / 2 : 0;
+          scheduledToday?.count && anyDeliveredToday ? Math.round(scheduledToday?.count) / 2 : 0;
         return { date, value };
       }),
       style: {