diff --git a/src/resolvers/MutationResolvers.ts b/src/resolvers/MutationResolvers.ts
index 9b48a7d..8d266c8 100644
--- a/src/resolvers/MutationResolvers.ts
+++ b/src/resolvers/MutationResolvers.ts
@@ -1,21 +1,47 @@
-import { NotificationResponse, Resolvers } from "../generated/graphql";
+import { MutationScheduleNotificationArgs, NotificationResponse, Resolvers } from "../generated/graphql";
 import { ServerContext } from "../ServerContext";
 import {
   ETANotificationScheduler,
 } from "../notifications/schedulers/ETANotificationScheduler";
 import { ScheduledNotification } from "../repositories/NotificationRepository";
+import { InterchangeSystem } from "../entities/InterchangeSystem";
+
+async function temp_findMatchingSystemBasedOnShuttleId(context: ServerContext, args: Omit<MutationScheduleNotificationArgs, "input"> & {
+  input: NonNullable<MutationScheduleNotificationArgs["input"]>
+}) {
+  let matchingSystem: InterchangeSystem | undefined;
+  await Promise.all(context.systems.map(async (system) => {
+    const shuttle = await system.shuttleRepository.getShuttleById(args.input.shuttleId);
+    // Theoretically, there should only be one
+    if (shuttle !== null) {
+      matchingSystem = system;
+    }
+    return shuttle;
+  }));
+  return matchingSystem;
+}
 
 export const MutationResolvers: Resolvers<ServerContext> = {
+  // TODO: Require system ID on these endpoints
   Mutation: {
     scheduleNotification: async (_parent, args, context, _info) => {
-      const shuttle = await context.shuttleRepository.getShuttleById(args.input.shuttleId);
+      let matchingSystem = await temp_findMatchingSystemBasedOnShuttleId(context, args);
+
+      if (!matchingSystem) {
+        return {
+          message: "Shuttle ID doesn't exist",
+          success: false,
+        }
+      }
+
+      const shuttle = await matchingSystem.shuttleRepository.getShuttleById(args.input.shuttleId);
       if (!shuttle) {
         return {
           message: "Shuttle ID doesn't exist",
           success: false,
         }
       }
-      const stop = await context.shuttleRepository.getStopById(args.input.stopId);
+      const stop = await matchingSystem.shuttleRepository.getStopById(args.input.stopId);
       if (!stop) {
         return {
           message: "Stop ID doesn't exist",
@@ -30,7 +56,7 @@ export const MutationResolvers: Resolvers<ServerContext> = {
           : ETANotificationScheduler.defaultSecondsThresholdForNotificationToFire,
       }
 
-      await context.notificationRepository.addOrUpdateNotification(notificationData);
+      await matchingSystem.notificationRepository.addOrUpdateNotification(notificationData);
 
       const response: NotificationResponse = {
         message: "Notification scheduled",
@@ -40,9 +66,18 @@ export const MutationResolvers: Resolvers<ServerContext> = {
       return response;
     },
     cancelNotification: async (_parent, args, context, _info) => {
-      const isScheduled = await context.notificationRepository.isNotificationScheduled(args.input)
+      const matchingSystem = await temp_findMatchingSystemBasedOnShuttleId(context, args);
+      if (!matchingSystem) {
+        return {
+          success: false,
+          message: "Unable to find correct system",
+          data: args.input,
+        }
+      }
+
+      const isScheduled = await matchingSystem.notificationRepository.isNotificationScheduled(args.input)
       if (isScheduled) {
-        await context.notificationRepository.deleteNotificationIfExists(args.input);
+        await matchingSystem.notificationRepository.deleteNotificationIfExists(args.input);
         return {
           success: true,
           message: "Notification cancelled",