diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index 76d2d2d64..90ea19bd4 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -23,11 +23,11 @@ from distutils.util import strtobool
 class RegistrationConfig(Config):
 
     def read_config(self, config):
-        self.disable_registration = not bool(
+        self.enable_registration = bool(
             strtobool(str(config["enable_registration"]))
         )
         if "disable_registration" in config:
-            self.disable_registration = bool(
+            self.enable_registration = not bool(
                 strtobool(str(config["disable_registration"]))
             )
 
@@ -78,6 +78,6 @@ class RegistrationConfig(Config):
 
     def read_arguments(self, args):
         if args.enable_registration is not None:
-            self.disable_registration = not bool(
+            self.enable_registration = bool(
                 strtobool(str(args.enable_registration))
             )
diff --git a/synapse/rest/client/v1/register.py b/synapse/rest/client/v1/register.py
index 2bfd4d96b..6d6d03c34 100644
--- a/synapse/rest/client/v1/register.py
+++ b/synapse/rest/client/v1/register.py
@@ -59,7 +59,7 @@ class RegisterRestServlet(ClientV1RestServlet):
         # }
         # TODO: persistent storage
         self.sessions = {}
-        self.disable_registration = hs.config.disable_registration
+        self.enable_registration = hs.config.enable_registration
 
     def on_GET(self, request):
         if self.hs.config.enable_registration_captcha:
@@ -113,7 +113,7 @@ class RegisterRestServlet(ClientV1RestServlet):
             is_using_shared_secret = login_type == LoginType.SHARED_SECRET
 
             can_register = (
-                not self.disable_registration
+                self.enable_registration
                 or is_application_server
                 or is_using_shared_secret
             )
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index 56a5bbec3..ec5c21fa1 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -117,7 +117,7 @@ class RegisterRestServlet(RestServlet):
             return
 
         # == Normal User Registration == (everyone else)
-        if self.hs.config.disable_registration:
+        if not self.hs.config.enable_registration:
             raise SynapseError(403, "Registration has been disabled")
 
         guest_access_token = body.get("guest_access_token", None)
diff --git a/tests/rest/client/v1/test_events.py b/tests/rest/client/v1/test_events.py
index b260e269a..e9698bfdc 100644
--- a/tests/rest/client/v1/test_events.py
+++ b/tests/rest/client/v1/test_events.py
@@ -122,7 +122,7 @@ class EventStreamPermissionsTestCase(RestTestCase):
         self.ratelimiter = hs.get_ratelimiter()
         self.ratelimiter.send_message.return_value = (True, 0)
         hs.config.enable_registration_captcha = False
-        hs.config.disable_registration = False
+        hs.config.enable_registration = True
 
         hs.get_handlers().federation_handler = Mock()
 
diff --git a/tests/rest/client/v2_alpha/test_register.py b/tests/rest/client/v2_alpha/test_register.py
index f9a2b2248..df0841b0b 100644
--- a/tests/rest/client/v2_alpha/test_register.py
+++ b/tests/rest/client/v2_alpha/test_register.py
@@ -41,7 +41,7 @@ class RegisterRestServletTestCase(unittest.TestCase):
         self.hs.hostname = "superbig~testing~thing.com"
         self.hs.get_auth = Mock(return_value=self.auth)
         self.hs.get_handlers = Mock(return_value=self.handlers)
-        self.hs.config.disable_registration = False
+        self.hs.config.enable_registration = True
 
         # init the thing we're testing
         self.servlet = RegisterRestServlet(self.hs)
@@ -120,7 +120,7 @@ class RegisterRestServletTestCase(unittest.TestCase):
         }))
 
     def test_POST_disabled_registration(self):
-        self.hs.config.disable_registration = True
+        self.hs.config.enable_registration = False
         self.request_data = json.dumps({
             "username": "kermit",
             "password": "monkey"
diff --git a/tests/utils.py b/tests/utils.py
index 431252a6f..3b1eb50d8 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -46,7 +46,7 @@ def setup_test_homeserver(name="test", datastore=None, config=None, **kargs):
         config = Mock()
         config.signing_key = [MockKey()]
         config.event_cache_size = 1
-        config.disable_registration = False
+        config.enable_registration = True
         config.macaroon_secret_key = "not even a little secret"
         config.server_name = "server.under.test"
         config.trusted_third_party_id_servers = []