diff --git a/integraality/tests/test_app.py b/integraality/tests/test_app.py
index 0b21075..9e33a49 100644
--- a/integraality/tests/test_app.py
+++ b/integraality/tests/test_app.py
@@ -1,16 +1,21 @@
 # -*- coding: utf-8  -*-
 import unittest
 
 from app import app
 
 
 class AppTests(unittest.TestCase):
 
     def setUp(self):
         app.config['TESTING'] = True
         self.app = app.test_client()
 
     def test_index_page(self):
         response = self.app.get('/')
         self.assertEqual(response.status_code, 200)
         self.assertIn("<h1>InteGraality</h1>", response.get_data(as_text=True))
+
+    def test_404_page(self):
+        response = self.app.get('/unexisting_page')
+        self.assertEqual(response.status_code, 404)
+        self.assertIn("This page does not exist.", response.get_data(as_text=True))