diff --git a/tests/sqlalchemy/test_dialect.py b/tests/sqlalchemy/test_dialect.py
index 1f47d2ff..24213ebf 100644
--- a/tests/sqlalchemy/test_dialect.py
+++ b/tests/sqlalchemy/test_dialect.py
@@ -19,12 +19,12 @@ def setup(self):
     @pytest.mark.parametrize(
         'url, expected_args, expected_kwargs',
         [
-            (make_url('trino://localhost'),
-             list(), dict(host='localhost', catalog='system', user='anonymous')),
-            (make_url('trino://1.2.3.4:4321/mysql/sakila'),
-             list(), dict(host='1.2.3.4', port=4321, catalog='mysql', schema='sakila', user='anonymous')),
+            (make_url('trino://user@localhost'),
+             list(), dict(host='localhost', catalog='system', user='user')),
+
             (make_url('trino://user@localhost:8080'),
              list(), dict(host='localhost', port=8080, catalog='system', user='user')),
+
             (make_url('trino://user:pass@localhost:8080'),
              list(), dict(host='localhost', port=8080, catalog='system', user='user',
                           auth=BasicAuthentication('user', 'pass'), http_scheme='https')),
@@ -36,6 +36,18 @@ def test_create_connect_args(self, url: URL, expected_args: List[Any], expected_
         assert_that(actual_args).is_equal_to(expected_args)
         assert_that(actual_kwargs).is_equal_to(expected_kwargs)
 
+    def test_create_connect_args_missing_user(self):
+        url = make_url('trino://localhost')
+        assert_that(self.dialect.create_connect_args).raises(ValueError) \
+            .when_called_with(url) \
+            .is_equal_to('user is required')
+
+    def test_create_connect_args_wrong_db_format(self):
+        url = make_url('trino://abc@localhost/catalog/schema/foobar')
+        assert_that(self.dialect.create_connect_args).raises(ValueError) \
+            .when_called_with(url) \
+            .is_equal_to('Unexpected database format catalog/schema/foobar')
+
     def test_get_default_isolation_level(self):
         isolation_level = self.dialect.get_default_isolation_level(mock.Mock())
         assert_that(isolation_level).is_equal_to('AUTOCOMMIT')
diff --git a/trino/sqlalchemy/dialect.py b/trino/sqlalchemy/dialect.py
index 969238b8..1fd22f84 100644
--- a/trino/sqlalchemy/dialect.py
+++ b/trino/sqlalchemy/dialect.py
@@ -10,7 +10,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 from textwrap import dedent
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Mapping, Optional, Sequence, Tuple
 
 from sqlalchemy import exc, sql
 from sqlalchemy.engine.base import Connection
@@ -58,10 +58,14 @@ def dbapi(cls):
         """
         return trino_dbapi
 
-    def create_connect_args(self, url: URL) -> Tuple[List[Any], Dict[str, Any]]:
-        args, kwargs = super(TrinoDialect, self).create_connect_args(url)  # type: List[Any], Dict[str, Any]
+    def create_connect_args(self, url: URL) -> Tuple[Sequence[Any], Mapping[str, Any]]:
+        args = list()
+        kwargs = dict(host=url.host)
 
-        db_parts = kwargs.pop('database', 'system').split('/')
+        if url.port:
+            kwargs['port'] = url.port
+
+        db_parts = (url.database or 'system').split('/')
         if len(db_parts) == 1:
             kwargs['catalog'] = db_parts[0]
         elif len(db_parts) == 2:
@@ -70,13 +74,13 @@ def create_connect_args(self, url: URL) -> Tuple[List[Any], Dict[str, Any]]:
         else:
             raise ValueError(f'Unexpected database format {url.database}')
 
-        username = kwargs.pop('username', 'anonymous')
-        kwargs['user'] = username
+        if not url.username:
+            raise ValueError(f"user is required")
+        kwargs['user'] = url.username
 
-        password = kwargs.pop('password', None)
-        if password:
+        if url.password:
             kwargs['http_scheme'] = 'https'
-            kwargs['auth'] = BasicAuthentication(username, password)
+            kwargs['auth'] = BasicAuthentication(url.username, url.password)
 
         return args, kwargs