diff --git a/tests/test_configurer.py b/tests/test_configurer.py
index fa3090e..5380861 100644
--- a/tests/test_configurer.py
+++ b/tests/test_configurer.py
@@ -2,6 +2,7 @@
 Test configurer
 """
 
+from traitlets import Dict
 import os
 import sys
 
@@ -62,6 +63,22 @@ def apply_mock_config(overrides):
     return c
 
 
+def test_default_base_url():
+    """
+    Test default JupyterHub base_url
+    """
+    c = apply_mock_config({})
+    assert c.JupyterHub.base_url == '/'
+
+
+def test_set_base_url():
+    """
+    Test set JupyterHub base_url
+    """
+    c = apply_mock_config({'base_url': '/custom-base'})
+    assert c.JupyterHub.base_url == '/custom-base'
+
+
 def test_default_memory_limit():
     """
     Test default per user memory limit
@@ -129,7 +146,7 @@ def test_auth_dummy():
     assert c.JupyterHub.authenticator_class == 'dummyauthenticator.DummyAuthenticator'
     assert c.DummyAuthenticator.password == 'test'
 
-from traitlets import Dict
+
 def test_user_groups():
     """
     Test setting user groups
@@ -143,9 +160,9 @@ def test_user_groups():
         }
     })
     assert c.UserCreatingSpawner.user_groups == {
-                "g1": ["u1", "u2"],
-                "g2": ["u3", "u4"]
-            }
+        "g1": ["u1", "u2"],
+        "g2": ["u3", "u4"]
+    }
 
 
 def test_auth_firstuse():
@@ -213,9 +230,9 @@ def test_cull_service_default():
     c = apply_mock_config({})
 
     cull_cmd = [
-       sys.executable, '-m', 'jupyterhub_idle_culler',
-       '--timeout=600', '--cull-every=60', '--concurrency=5',
-       '--max-age=0'
+        sys.executable, '-m', 'jupyterhub_idle_culler',
+        '--timeout=600', '--cull-every=60', '--concurrency=5',
+        '--max-age=0'
     ]
     assert c.JupyterHub.services == [{
         'name': 'cull-idle',
@@ -238,9 +255,9 @@ def test_set_cull_service():
         }
     })
     cull_cmd = [
-       sys.executable, '-m', 'jupyterhub_idle_culler',
-       '--timeout=600', '--cull-every=10', '--concurrency=5',
-       '--max-age=60', '--cull-users'
+        sys.executable, '-m', 'jupyterhub_idle_culler',
+        '--timeout=600', '--cull-every=10', '--concurrency=5',
+        '--max-age=60', '--cull-users'
     ]
     assert c.JupyterHub.services == [{
         'name': 'cull-idle',
@@ -276,4 +293,3 @@ def test_auth_native():
     })
     assert c.JupyterHub.authenticator_class == 'nativeauthenticator.NativeAuthenticator'
     assert c.NativeAuthenticator.open_signup == True
-
diff --git a/tljh/config.py b/tljh/config.py
index a30f176..ec235f4 100644
--- a/tljh/config.py
+++ b/tljh/config.py
@@ -61,6 +61,7 @@ def set_item_in_config(config, property_path, value):
 
     return config_copy
 
+
 def unset_item_from_config(config, property_path):
     """
     Unset key at property_path in config & return new config.
@@ -105,6 +106,7 @@ def unset_item_from_config(config, property_path):
 
     return config_copy
 
+
 def add_item_to_config(config, property_path, value):
     """
     Add an item to a list in config.
@@ -238,6 +240,7 @@ def remove_config_value(config_path, key_path, value):
     with open(config_path, 'w') as f:
         yaml.dump(config, f)
 
+
 def check_hub_ready():
     from .configurer import load_config
 
@@ -250,6 +253,7 @@ def check_hub_ready():
     except:
         return False
 
+
 def reload_component(component):
     """
     Reload a TLJH component.
@@ -392,13 +396,16 @@ def main(argv=None):
     if args.action == 'show':
         show_config(args.config_path)
     elif args.action == 'set':
-        set_config_value(args.config_path, args.key_path, parse_value(args.value))
+        set_config_value(args.config_path, args.key_path,
+                         parse_value(args.value))
     elif args.action == 'unset':
         unset_config_value(args.config_path, args.key_path)
     elif args.action == 'add-item':
-        add_config_value(args.config_path, args.key_path, parse_value(args.value))
+        add_config_value(args.config_path, args.key_path,
+                         parse_value(args.value))
     elif args.action == 'remove-item':
-        remove_config_value(args.config_path, args.key_path, parse_value(args.value))
+        remove_config_value(args.config_path, args.key_path,
+                            parse_value(args.value))
     elif args.action == 'reload':
         reload_component(args.component)
     else: