diff --git a/README.md b/README.md
index 40ec25c..01f88b2 100644
--- a/README.md
+++ b/README.md
@@ -49,6 +49,8 @@ The application will be visible http://localhost:8081
 - Login to playwright container with `docker exec -ti species-challenge-playwright-1 bash`
 - Run tests with `python -m pytest -v -s`. The `-s` option enables print outputs.
 
+- Note: if tests fail with `page.goto("http://web:8081/login?token=nonrealtoken")`, restart the Docker containers and try again.
+
 ## Deploying to Rahti 2
 
 - Run e2e-tests
diff --git a/app/main.py b/app/main.py
index d431f12..646e84b 100644
--- a/app/main.py
+++ b/app/main.py
@@ -70,6 +70,17 @@ def before_request():
     # Make itsystem_id available for controllers
     g.itsystem_name = get_version_info()
 
+@app.after_request
+def set_security_headers(response):
+    response.headers['Strict-Transport-Security'] = 'max-age=31536000; includeSubDomains'
+    response.headers['Content-Security-Policy'] = "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'"
+    response.headers['X-Content-Type-Options'] = 'nosniff'
+    response.headers['X-Frame-Options'] = 'SAMEORIGIN'
+    response.headers['Referrer-Policy'] = 'strict-origin-when-cross-origin'
+    response.headers['X-Permitted-Cross-Domain-Policies'] = 'none'
+    response.headers['Feature-Policy'] = "microphone 'none'"
+    return response
+
 # Make data available for templates
 @app.context_processor
 def inject_data():
diff --git a/tests-playwright/requirements.txt b/tests-playwright/requirements.txt
index 8e4d701..fab88bc 100644
--- a/tests-playwright/requirements.txt
+++ b/tests-playwright/requirements.txt
@@ -1,2 +1,2 @@
-pytest
-pytest-playwright
+pytest == 8.3.*
+pytest-playwright == 0.6.*
diff --git a/tests-playwright/test_admin_login.py b/tests-playwright/test_admin_login.py
index a8965de..6d46eca 100644
--- a/tests-playwright/test_admin_login.py
+++ b/tests-playwright/test_admin_login.py
@@ -6,6 +6,7 @@
 
 from urllib.parse import urljoin, urlparse, parse_qs
 
+
 def extract_token(url):
     parsed_url = urlparse(url)
     query_params = parse_qs(parsed_url.query)
@@ -59,7 +60,7 @@ def test_login_and_save_state(browser):
 
     # Issue: Playwright cannot follow these login redirections, but gets stuck at /login.
     # Workaround: extract token and navigate to /login manually.
-    token = extract_token(page.url)
+    token = extract_token(page.url)    
     page.goto("http://web:8081/login?token=" + token)
 
     page.wait_for_selector('#logout')