diff --git a/src/Queue/ActionQueue.ts b/src/Queue/ActionQueue.ts
index 38eae4d..5614ac4 100644
--- a/src/Queue/ActionQueue.ts
+++ b/src/Queue/ActionQueue.ts
@@ -5,7 +5,9 @@ import { DataStorage } from '../DataStorage';
 const NAMESPACE = 'actions.v1';
 const QUEUE_NAME = 'queue';
 
-export type ActionList = Array<Command>;
+type ActionList = Array<Command>;
+
+export type ImmutableActionList = ReadonlyArray<Command>;
 
 export class ActionQueue {
     private storage: DataStorage;
@@ -37,7 +39,7 @@ export class ActionQueue {
         this.flushState([]);
     }
 
-    seeItems(): ActionList {
+    seeItems(): ImmutableActionList {
         return this.getCommands();
     }
 
diff --git a/src/Queue/TaskQueue.ts b/src/Queue/TaskQueue.ts
index 61271af..5782a79 100644
--- a/src/Queue/TaskQueue.ts
+++ b/src/Queue/TaskQueue.ts
@@ -34,7 +34,9 @@ export class Task {
     }
 }
 
-export type TaskList = Array<Task>;
+type TaskList = Array<Task>;
+
+export type ImmutableTaskList = ReadonlyArray<Task>;
 
 export class TaskQueue {
     private readonly logger: Logger;
@@ -79,7 +81,7 @@ export class TaskQueue {
         this.flushItems(items);
     }
 
-    seeItems(): TaskList {
+    seeItems(): ImmutableTaskList {
         return this.getItems();
     }
 
diff --git a/src/Scheduler.ts b/src/Scheduler.ts
index 6a4c095..762e2db 100644
--- a/src/Scheduler.ts
+++ b/src/Scheduler.ts
@@ -1,13 +1,13 @@
 import { timestamp } from './utils';
 import { UpgradeBuildingTask } from './Task/UpgradeBuildingTask';
-import { Task, TaskId, TaskList, TaskQueue } from './Queue/TaskQueue';
+import { ImmutableTaskList, Task, TaskId, TaskQueue } from './Queue/TaskQueue';
 import { Args, Command } from './Command';
 import { SendOnAdventureTask } from './Task/SendOnAdventureTask';
 import { BalanceHeroResourcesTask } from './Task/BalanceHeroResourcesTask';
 import { ConsoleLogger, Logger } from './Logger';
 import { BuildBuildingTask } from './Task/BuildBuildingTask';
 import { GrabVillageState } from './Task/GrabVillageState';
-import { ActionList, ActionQueue } from './Queue/ActionQueue';
+import { ActionQueue, ImmutableActionList } from './Queue/ActionQueue';
 import { Resources, ResourcesInterface } from './Game';
 import { UpdateResourceContracts } from './Task/UpdateResourceContracts';
 import { TrainTroopTask } from './Task/TrainTroopTask';
@@ -40,11 +40,11 @@ export class Scheduler {
         setInterval(taskScheduler, seconds * 1000);
     }
 
-    getTaskItems(): TaskList {
+    getTaskItems(): ImmutableTaskList {
         return this.taskQueue.seeItems();
     }
 
-    getActionItems(): ActionList {
+    getActionItems(): ImmutableActionList {
         return this.actionQueue.seeItems();
     }
 
@@ -161,11 +161,11 @@ function withResources(task: Task, resources: ResourcesInterface): Task {
     return new Task(task.id, task.ts, task.name, { ...task.args, resources });
 }
 
-function firstTaskTime(tasks: TaskList, predicate: (t: Task) => boolean): number | undefined {
+function firstTaskTime(tasks: ImmutableTaskList, predicate: (t: Task) => boolean): number | undefined {
     return tasks.find(predicate)?.ts;
 }
 
-function lastTaskTime(tasks: TaskList, predicate: (t: Task) => boolean): number | undefined {
+function lastTaskTime(tasks: ImmutableTaskList, predicate: (t: Task) => boolean): number | undefined {
     const queuedTaskIndex = findLastIndex(tasks, predicate);
     if (queuedTaskIndex === undefined) {
         return undefined;
@@ -173,7 +173,7 @@ function lastTaskTime(tasks: TaskList, predicate: (t: Task) => boolean): number
     return tasks[queuedTaskIndex].ts;
 }
 
-function findLastIndex(tasks: TaskList, predicate: (t: Task) => boolean): number | undefined {
+function findLastIndex(tasks: ImmutableTaskList, predicate: (t: Task) => boolean): number | undefined {
     const count = tasks.length;
     const indexInReversed = tasks
         .slice()
diff --git a/src/TaskQueueRenderer.ts b/src/TaskQueueRenderer.ts
index 870a571..5b19723 100644
--- a/src/TaskQueueRenderer.ts
+++ b/src/TaskQueueRenderer.ts
@@ -1,4 +1,4 @@
-import { TaskList } from './Queue/TaskQueue';
+import { ImmutableTaskList } from './Queue/TaskQueue';
 import { uniqId } from './utils';
 import * as dateFormat from 'dateformat';
 
@@ -10,7 +10,7 @@ function formatDate(ts: number) {
 }
 
 export class TaskQueueRenderer {
-    render(tasks: TaskList) {
+    render(tasks: ImmutableTaskList) {
         const ul = jQuery('<ul></ul>')
             .attr({ id: ID })
             .css({