diff --git a/Sprint-3/todo-list/todos.mjs b/Sprint-3/todo-list/todos.mjs
index f17ab6a25..1e25e194c 100644
--- a/Sprint-3/todo-list/todos.mjs
+++ b/Sprint-3/todo-list/todos.mjs
@@ -16,14 +16,14 @@ export function addTask(todos, task, completed = false) {
 
 // Delete todos[taskIndex] if it exists
 export function deleteTask(todos, taskIndex) {
-  if (todos[taskIndex]) {
+  if (taskIndex >= 0 && taskIndex < todos.length) {
     todos.splice(taskIndex, 1);
   }
 }
 
 // Toggle the "completed" property of todos[taskIndex] if the task exists.
 export function toggleCompletedOnTask(todos, taskIndex) {
-  if (todos[taskIndex]) {
+  if (taskIndex >= 0 && taskIndex < todos.length) {
     todos[taskIndex].completed = !todos[taskIndex].completed;
   }
-}
\ No newline at end of file
+}
diff --git a/Sprint-3/todo-list/todos.test.mjs b/Sprint-3/todo-list/todos.test.mjs
index bae7ae491..a00b82b71 100644
--- a/Sprint-3/todo-list/todos.test.mjs
+++ b/Sprint-3/todo-list/todos.test.mjs
@@ -13,7 +13,7 @@ function createMockTodos() {
     { task: "Task 1 description", completed: true },
     { task: "Task 2 description", completed: false },
     { task: "Task 3 description", completed: true },
-    { task: "Task 4 description", completed: false },        
+    { task: "Task 4 description", completed: false },
   ];
 }
 
@@ -29,7 +29,6 @@ describe("addTask()", () => {
   });
 
   test("Should append a new task to the end of a ToDo list", () => {
-
     const todos = createMockTodos();
     const lengthBeforeAddition = todos.length;
     Todos.addTask(todos, theTask.task, theTask.completed);
@@ -42,7 +41,6 @@ describe("addTask()", () => {
 });
 
 describe("deleteTask()", () => {
-
   test("Delete the first task", () => {
     const todos = createMockTodos();
     const todosBeforeDeletion = createMockTodos();
@@ -53,7 +51,7 @@ describe("deleteTask()", () => {
 
     expect(todos[0]).toEqual(todosBeforeDeletion[1]);
     expect(todos[1]).toEqual(todosBeforeDeletion[2]);
-    expect(todos[2]).toEqual(todosBeforeDeletion[3]);        
+    expect(todos[2]).toEqual(todosBeforeDeletion[3]);
   });
 
   test("Delete the second task (a middle task)", () => {
@@ -66,7 +64,7 @@ describe("deleteTask()", () => {
 
     expect(todos[0]).toEqual(todosBeforeDeletion[0]);
     expect(todos[1]).toEqual(todosBeforeDeletion[2]);
-    expect(todos[2]).toEqual(todosBeforeDeletion[3]);        
+    expect(todos[2]).toEqual(todosBeforeDeletion[3]);
   });
 
   test("Delete the last task", () => {
@@ -79,7 +77,7 @@ describe("deleteTask()", () => {
 
     expect(todos[0]).toEqual(todosBeforeDeletion[0]);
     expect(todos[1]).toEqual(todosBeforeDeletion[1]);
-    expect(todos[2]).toEqual(todosBeforeDeletion[2]);        
+    expect(todos[2]).toEqual(todosBeforeDeletion[2]);
   });
 
   test("Delete a non-existing task", () => {
@@ -94,7 +92,6 @@ describe("deleteTask()", () => {
 });
 
 describe("toggleCompletedOnTask()", () => {
-
   test("Expect the 'completed' property to toggle on an existing task", () => {
     const todos = createMockTodos();
     const taskIndex = 1;
@@ -111,13 +108,12 @@ describe("toggleCompletedOnTask()", () => {
     const todos = createMockTodos();
     const todosBeforeToggle = createMockTodos();
     Todos.toggleCompletedOnTask(todos, 1);
-    
-    expect(todos[0]).toEqual(todosBeforeToggle[0]);    
+
+    expect(todos[0]).toEqual(todosBeforeToggle[0]);
     expect(todos[2]).toEqual(todosBeforeToggle[2]);
     expect(todos[3]).toEqual(todosBeforeToggle[3]);
   });
 
-
   test("Expect no change when toggling on a non-existing task", () => {
     const todos = createMockTodos();
     const todosBeforeToggle = createMockTodos();
@@ -129,4 +125,3 @@ describe("toggleCompletedOnTask()", () => {
     expect(todos).toEqual(todosBeforeToggle);
   });
 });
-