diff --git a/tests/test_cursor.py b/tests/test_cursor.py
index e896ef94..5c94f422 100755
--- a/tests/test_cursor.py
+++ b/tests/test_cursor.py
@@ -553,7 +553,7 @@ class CursorTests(ConnectingTestCase):
         # Issue #443 is in the async code too. Since the fix is duplicated,
         # so is the test.
         control_conn = self.conn
-        connect_func = lambda: self.connect(async=True)
+        connect_func = lambda: self.connect(async_=True)
         wait_func = psycopg2.extras.wait_select
         self._test_external_close(control_conn, connect_func, wait_func)