diff --git a/dallinger/experiment_server/experiment_server.py b/dallinger/experiment_server/experiment_server.py
index <HASH>..<HASH> 100644
--- a/dallinger/experiment_server/experiment_server.py
+++ b/dallinger/experiment_server/experiment_server.py
@@ -66,7 +66,7 @@ else:
 @app.route('/')
 def index():
     """Index route"""
-    return render_template('default.html')
+    abort(404)
 
 
 @app.route('/robots.txt')
diff --git a/tests/test_experiment_server.py b/tests/test_experiment_server.py
index <HASH>..<HASH> 100644
--- a/tests/test_experiment_server.py
+++ b/tests/test_experiment_server.py
@@ -54,9 +54,9 @@ class TestExperimentServer(FlaskAppTest):
         participant = Participant.query.get(participant_id)
         participant.status = status
 
-    def test_default(self):
+    def test_root(self):
         resp = self.app.get('/')
-        assert 'Welcome to Dallinger!' in resp.data
+        assert resp.status_code == 404
 
     def test_favicon(self):
         resp = self.app.get('/favicon.ico')
Return <I> instead of non-existent template

Closes #<I>. (Eventually, this should return the ad page with random
credentials.)