diff --git a/test-apps/test-api/client.ts b/test-apps/test-api/client.ts
index d38a9e3..76d7605 100644
--- a/test-apps/test-api/client.ts
+++ b/test-apps/test-api/client.ts
@@ -274,7 +274,7 @@ export const TestAPIExamples = {
   /**
    * Error handling example
    */
-  async errorHandling() {
+  async errorHandling(): Promise<void> {
     const client = new TestAPIClient(getAPIConfig());
     
     // console.log('Testing error handling...');
@@ -290,7 +290,7 @@ export const TestAPIExamples = {
   /**
    * Health check example
    */
-  async healthCheck() {
+  async healthCheck(): Promise<void> {
     const client = new TestAPIClient(getAPIConfig());
     
     // console.log('Testing health check...');
diff --git a/tests/setup.ts b/tests/setup.ts
index 20f9e2d..d718e6e 100644
--- a/tests/setup.ts
+++ b/tests/setup.ts
@@ -40,8 +40,8 @@ global.Response = jest.fn().mockImplementation(() => mockResponse) as unknown as
 
 // Mock Date
 global.Date = jest.fn().mockImplementation(() => ({
-  getTime: () => 0,
-  toISOString: () => '2024-01-01T00:00:00.000Z',
+  getTime: (): number => 0,
+  toISOString: (): string => '2024-01-01T00:00:00.000Z',
 })) as unknown as typeof Date;
 
 // Clean up mocks after each test