diff --git a/tests/test_deconstruct.py b/tests/test_deconstruct.py
index 2a9614d..ec4c276 100644
--- a/tests/test_deconstruct.py
+++ b/tests/test_deconstruct.py
@@ -108,13 +108,16 @@ def test_specifying_defaults_not_frozen():
     ],
 )
 def test_deconstruct_when_using_choices(choices, use_pytz):
-    field = TimeZoneField(choices=choices)
-    _name, _path, args, kwargs = field.deconstruct()
+    field = TimeZoneField(choices=choices, use_pytz=use_pytz)
+    _name, _path, _args, kwargs = field.deconstruct()
     assert kwargs == {
-        "choices": [
-            ("US/Pacific", "US/Pacific"),
-            ("US/Eastern", "US/Eastern"),
-        ]
+        **{
+            "choices": [
+                ("US/Pacific", "US/Pacific"),
+                ("US/Eastern", "US/Eastern"),
+            ]
+        },
+        **({"use_pytz": use_pytz} if use_pytz is not None else {}),
     }
 
 
diff --git a/timezone_field/fields.py b/timezone_field/fields.py
index 5a5b21a..8a195c4 100644
--- a/timezone_field/fields.py
+++ b/timezone_field/fields.py
@@ -46,8 +46,8 @@ def __init__(self, *args, **kwargs):
         # https://github.com/django/django/blob/1.11.11/django/db/models/fields/__init__.py#L145
         if len(args) > 3:
             raise ValueError("Cannot specify max_length by positional arg")
+        kwargs.setdefault("max_length", self.default_max_length)
 
-        self.max_length = kwargs.pop("max_length", self.default_max_length)
         self.use_pytz_explicit = kwargs.pop("use_pytz", None)
         self.use_pytz = self.use_pytz_explicit if self.use_pytz_explicit is not None else use_pytz_default()
         self.default_tzs = self.default_pytz_tzs if self.use_pytz else self.default_zoneinfo_tzs