diff --git a/mopidy/utils/http.py b/mopidy/utils/http.py
index f0c658e7..096a37a0 100644
--- a/mopidy/utils/http.py
+++ b/mopidy/utils/http.py
@@ -25,7 +25,7 @@ def format_proxy(proxy_config):
     if port < 0:
         port = 80
 
-    return template.format(scheme=proxy_config.get('scheme', 'http'),
+    return template.format(scheme=proxy_config.get('scheme') or 'http',
                            username=proxy_config.get('username'),
                            password=proxy_config.get('password'),
                            hostname=proxy_config['hostname'], port=port)
diff --git a/tests/utils/test_http.py b/tests/utils/test_http.py
index cf97e57c..dee09c3c 100644
--- a/tests/utils/test_http.py
+++ b/tests/utils/test_http.py
@@ -10,6 +10,7 @@ from mopidy.utils import http
 @pytest.mark.parametrize("config,expected", [
     ({}, None),
     ({'hostname': 'proxy.lan'}, 'http://proxy.lan:80'),
+    ({'scheme': None, 'hostname': 'proxy.lan'}, 'http://proxy.lan:80'),
     ({'scheme': 'https', 'hostname': 'proxy.lan'}, 'https://proxy.lan:80'),
     ({'username': 'user', 'hostname': 'proxy.lan'}, 'http://proxy.lan:80'),
     ({'password': 'pass', 'hostname': 'proxy.lan'}, 'http://proxy.lan:80'),