diff --git a/src/entities/ParkingRepositoryEntities.ts b/src/entities/ParkingRepositoryEntities.ts
index f0dadea..b78a754 100644
--- a/src/entities/ParkingRepositoryEntities.ts
+++ b/src/entities/ParkingRepositoryEntities.ts
@@ -1,6 +1,6 @@
-import { ICoordinates, IEntityWithId, IEntityWithOptionalTimestamp } from "./SharedEntities";
+import { ICoordinates, IEntityWithId, IEntityWithTimestamp } from "./SharedEntities";
 
-export interface IParkingStructure extends IEntityWithOptionalTimestamp, IEntityWithId {
+export interface IParkingStructure extends IEntityWithTimestamp, IEntityWithId {
   address: string;
   capacity: number;
   spotsAvailable: number;
diff --git a/src/entities/SharedEntities.ts b/src/entities/SharedEntities.ts
index 9b92713..d23915a 100644
--- a/src/entities/SharedEntities.ts
+++ b/src/entities/SharedEntities.ts
@@ -1,4 +1,4 @@
-export interface IEntityWithOptionalTimestamp {
+export interface IEntityWithTimestamp {
   updatedTimeMs: number;
 }
 
diff --git a/src/entities/ShuttleRepositoryEntities.ts b/src/entities/ShuttleRepositoryEntities.ts
index 3ab9a29..608bda6 100644
--- a/src/entities/ShuttleRepositoryEntities.ts
+++ b/src/entities/ShuttleRepositoryEntities.ts
@@ -1,19 +1,19 @@
-import { ICoordinates, IEntityWithId, IEntityWithOptionalTimestamp } from "./SharedEntities";
+import { ICoordinates, IEntityWithId, IEntityWithTimestamp } from "./SharedEntities";
 
-export interface IRoute extends IEntityWithId, IEntityWithOptionalTimestamp {
+export interface IRoute extends IEntityWithId, IEntityWithTimestamp {
   name: string;
   color: string;
   polylineCoordinates: ICoordinates[];
   systemId: string;
 }
 
-export interface IStop extends IEntityWithId, IEntityWithOptionalTimestamp {
+export interface IStop extends IEntityWithId, IEntityWithTimestamp {
   name: string;
   systemId: string;
   coordinates: ICoordinates;
 }
 
-export interface IShuttle extends IEntityWithId, IEntityWithOptionalTimestamp {
+export interface IShuttle extends IEntityWithId, IEntityWithTimestamp {
   coordinates: ICoordinates;
   name: string;
   routeId: string;
@@ -21,14 +21,14 @@ export interface IShuttle extends IEntityWithId, IEntityWithOptionalTimestamp {
   orientationInDegrees: number;
 }
 
-export interface IEta extends IEntityWithOptionalTimestamp {
+export interface IEta extends IEntityWithTimestamp {
   secondsRemaining: number;
   shuttleId: string;
   stopId: string;
   systemId: string;
 }
 
-export interface IOrderedStop extends IEntityWithOptionalTimestamp {
+export interface IOrderedStop extends IEntityWithTimestamp {
   nextStop?: IOrderedStop;
   previousStop?: IOrderedStop;
   routeId: string;