diff --git a/repo2docker/app.py b/repo2docker/app.py
index 7f658852..73ac12c5 100644
--- a/repo2docker/app.py
+++ b/repo2docker/app.py
@@ -18,6 +18,7 @@ import tempfile
 import time
 
 import docker
+from urllib.parse import urlparse
 from docker.utils import kwargs_from_env
 from docker.errors import DockerException
 import escapism
@@ -520,11 +521,26 @@ class Repo2Docker(Application):
         Returns running container
         """
         client = docker.from_env(version='auto')
+
+        docker_host = os.environ.get('DOCKER_HOST')
+        if docker_host:
+            host_name = urlparse(docker_host).hostname
+        else:
+            host_name = '127.0.0.1'
+        self.hostname = host_name
+
         if not self.run_cmd:
             port = str(self._get_free_port())
             self.port = port
-            run_cmd = ['jupyter', 'notebook', '--ip', '0.0.0.0',
-                       '--port', port]
+            # To use the option --NotebookApp.custom_display_url
+            # make sure the base-notebook image is updated:
+            # docker pull jupyter/base-notebook
+            run_cmd = [
+                'jupyter', 'notebook',
+                '--ip', '0.0.0.0',
+                '--port', port,
+                "--NotebookApp.custom_display_url=http://{}:{}".format(host_name, port),
+            ]
             ports = {'%s/tcp' % port: port}
         else:
             # run_cmd given by user, if port is also given then pass it on
@@ -535,6 +551,7 @@ class Repo2Docker(Application):
                 ports = {}
         # store ports on self so they can be retrieved in tests
         self.ports = ports
+
         container_volumes = {}
         if self.volumes:
             api_client = docker.APIClient(
diff --git a/tests/test_connect_url.py b/tests/test_connect_url.py
new file mode 100644
index 00000000..5c5e1acf
--- /dev/null
+++ b/tests/test_connect_url.py
@@ -0,0 +1,52 @@
+"""
+Test if the explict hostname is supplied correctly to the container
+"""
+import requests
+import time
+from repo2docker.app import Repo2Docker
+
+def test_connect_url(tmpdir):
+    tmpdir.chdir()
+    #q = tmpdir.join("environment.yml")
+    #q.write("dependencies:\n"
+    #        "  -  notebook==5.6.0")
+    p = tmpdir.join("requirements.txt")
+    p.write("notebook==5.6.0")
+
+    app = Repo2Docker()
+    argv = [str(tmpdir), ]
+    app.initialize(argv)
+    app.debug = True
+    app.run = False
+    app.start()  # This just build the image and does not run it.
+    container = app.start_container()
+    container_url = 'http://{}:{}/api'.format(app.hostname, app.port)
+    expected_url = 'http://{}:{}'.format(app.hostname, app.port)
+
+    # wait a bit for the container to be ready
+    # give the container a chance to start
+    time.sleep(1)
+
+    try:
+        # try a few times to connect
+        success = False
+        for i in range(1, 4):
+            container.reload()
+            assert container.status == 'running'
+            if expected_url not in container.logs().decode("utf8"):
+                time.sleep(i * 3)
+                continue
+            try:
+                info = requests.get(container_url).json()
+            except Exception as e:
+                print("Error: %s" % e)
+                time.sleep(i * 3)
+            else:
+                print(info)
+                success = True
+                break
+        assert success, "Notebook never started in %s" % container
+    finally:
+        # stop the container
+        container.stop()
+        app.wait_for_container(container)