diff --git a/dj_database_url/__init__.py b/dj_database_url/__init__.py
index 8e9fa27..e93712c 100644
--- a/dj_database_url/__init__.py
+++ b/dj_database_url/__init__.py
@@ -127,7 +127,7 @@ def config(
     env: str = DEFAULT_ENV,
     default: Optional[str] = None,
     engine: Optional[str] = None,
-    conn_max_age: int = 0,
+    conn_max_age: Optional[int] = 0,
     conn_health_checks: bool = False,
     disable_server_side_cursors: bool = False,
     ssl_require: bool = False,
@@ -158,7 +158,7 @@ def config(
 def parse(
     url: str,
     engine: Optional[str] = None,
-    conn_max_age: int = 0,
+    conn_max_age: Optional[int] = 0,
     conn_health_checks: bool = False,
     disable_server_side_cursors: bool = False,
     ssl_require: bool = False,
@@ -231,7 +231,7 @@ def _parse_value(value: str) -> OptionType:
 
 def _convert_to_settings(
     engine: Optional[str],
-    conn_max_age: int,
+    conn_max_age: Optional[int],
     conn_health_checks: bool,
     disable_server_side_cursors: bool,
     ssl_require: bool,
diff --git a/tests/test_dj_database_url.py b/tests/test_dj_database_url.py
index f498796..7ab1398 100644
--- a/tests/test_dj_database_url.py
+++ b/tests/test_dj_database_url.py
@@ -266,8 +266,8 @@ class DatabaseTestSuite(unittest.TestCase):
 
         assert url["CONN_MAX_AGE"] == conn_max_age
 
-    def test_config_conn_max_age_setting(self) -> None:
-        conn_max_age = 600
+    def test_config_conn_max_age_setting_none(self) -> None:
+        conn_max_age = None
         with mock.patch.dict(
             os.environ,
             {