diff --git a/.travis.yml b/.travis.yml
index af5b21a..9c1a84f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,4 +21,7 @@ script:
  - docker-compose -p instance1 -f docker-compose-tests.yml ps
  - WEB_PORT=5007 CONFIG_DIR=./tests/fixtures/instance2/config docker-compose -p instance2 -f docker-compose-tests.yml up -d
  - docker-compose -p instance2 -f docker-compose-tests.yml ps
- - pytest -v --ignore data
+ # Integration tests first
+ - pytest -v --ignore data -k integration
+ # Federation tests (with two local instances)
+ - pytest -v -s --ignore data -k federation
diff --git a/app.py b/app.py
index fe0c444..db0d98c 100644
--- a/app.py
+++ b/app.py
@@ -760,6 +760,8 @@ def api_upload():
 @api_required                                      
 def api_new_note(): 
     source = request.args.get('content')
+    if not source:
+        raise ValueError('missing content')
     content, tags = parse_markdown(source)       
     to = request.args.get('to')
     cc = [ID+'/followers']
@@ -792,6 +794,8 @@ def api_stream():
 @api_required
 def api_follow():
     actor = request.args.get('actor')
+    if not actor:
+        raise ValueError('missing actor')
     if DB.following.find({'remote_actor': actor}).count() > 0:
         return Response(status=201)
 
diff --git a/config.py b/config.py
index 6002350..6cb17e6 100644
--- a/config.py
+++ b/config.py
@@ -43,7 +43,7 @@ with open('config/me.yml') as f:
     SUMMARY = conf['summary']
     ICON_URL = conf['icon_url']
     PASS = conf['pass']
-    PUBLIC_INSTANCES = conf.get('public_instances')
+    PUBLIC_INSTANCES = conf.get('public_instances', [])
     # TODO(tsileo): choose dark/light style
     THEME_COLOR = conf.get('theme_color')
 
diff --git a/docker-compose-tests.yml b/docker-compose-tests.yml
index af55d05..d45609b 100644
--- a/docker-compose-tests.yml
+++ b/docker-compose-tests.yml
@@ -1,4 +1,4 @@
-version: '3'
+version: '3.5'
 services:
   web:
     build: .
@@ -31,3 +31,6 @@ services:
     environment:
      - RABBITMQ_ERLANG_COOKIE=secretrabbit
      - RABBITMQ_NODENAME=rabbit@my-rabbit
+networks:
+  default:
+    name: microblogpubfede 
diff --git a/tests/federation_test.py b/tests/federation_test.py
new file mode 100644
index 0000000..f345dd0
--- /dev/null
+++ b/tests/federation_test.py
@@ -0,0 +1,41 @@
+import os
+
+import requests
+from html2text import html2text
+
+
+def resp2plaintext(resp):
+    """Convert the body of a requests reponse to plain text in order to make basic assertions."""
+    return html2text(resp.text)
+
+
+def test_federation():
+    """Ensure the homepage is accessible."""
+    resp = requests.get('http://localhost:5006')
+    resp.raise_for_status()
+    assert resp.status_code == 200
+
+    resp = requests.get('http://localhost:5007')
+    resp.raise_for_status()
+    assert resp.status_code == 200
+
+    # Keep one session per instance
+
+    # Login
+    session1 = requests.Session()
+    resp = session1.post('http://localhost:5006/login', data={'pass': 'hello'})
+    assert resp.status_code == 200
+
+    # Login
+    session2 = requests.Session()
+    resp = session2.post('http://localhost:5007/login', data={'pass': 'hello'})
+    assert resp.status_code == 200
+
+    # Instance1 follows instance2
+    resp = session1.get('http://localhost:5006/api/follow', params={'actor': 'http://instance2_web_1:5005'})
+    assert resp.status_code == 201
+
+    resp = requests.get('http://localhost:5007/followers', headers={'Accept': 'application/activity+json'})
+    resp.raise_for_status()
+
+    assert resp.json()['first']['orderedItems'] == ['http://instance1_web_1:5005']
diff --git a/tests/fixtures/instance1/config/me.yml b/tests/fixtures/instance1/config/me.yml
index 2513938..f7c803c 100644
--- a/tests/fixtures/instance1/config/me.yml
+++ b/tests/fixtures/instance1/config/me.yml
@@ -1,7 +1,7 @@
-username: 'instance_1'
+username: 'instance1'
 name: 'Instance 1'
 icon_url: 'https://sos-ch-dk-2.exo.io/microblogpub/microblobpub.png'
-domain: 'localhost:5006'
-summary: 'instance 1 summary'
+domain: 'instance1_web_1:5005'
+summary: 'instance1 summary'
 pass: '$2b$12$nEgJMgaYbXSPOvgnqM4jSeYnleKhXqsFgv/o3hg12x79uEdsR4cUy'  # hello
 https: false
diff --git a/tests/fixtures/instance2/config/me.yml b/tests/fixtures/instance2/config/me.yml
index 844e5c8..22f4127 100644
--- a/tests/fixtures/instance2/config/me.yml
+++ b/tests/fixtures/instance2/config/me.yml
@@ -1,7 +1,7 @@
-username: 'instance_2'
+username: 'instance2'
 name: 'Instance 2'
 icon_url: 'https://sos-ch-dk-2.exo.io/microblogpub/microblobpub.png'
-domain: 'localhost:5007'
-summary: 'instance 2 summary'
+domain: 'instance2_web_1:5005'
+summary: 'instance2 summary'
 pass: '$2b$12$nEgJMgaYbXSPOvgnqM4jSeYnleKhXqsFgv/o3hg12x79uEdsR4cUy'  # hello
 https: false