diff --git a/django/contrib/auth/tests/test_management.py b/django/contrib/auth/tests/test_management.py
index c60346c2ac..8a591fc7a9 100644
--- a/django/contrib/auth/tests/test_management.py
+++ b/django/contrib/auth/tests/test_management.py
@@ -196,21 +196,21 @@ class CustomUserModelValidationTestCase(TestCase):
     def test_required_fields_is_list(self):
         "REQUIRED_FIELDS should be a list."
         new_io = StringIO()
-        get_validation_errors(new_io, apps.get_app_config('auth').models_module)
+        get_validation_errors(new_io, apps.get_app_config('auth'))
         self.assertIn("The REQUIRED_FIELDS must be a list or tuple.", new_io.getvalue())
 
     @override_settings(AUTH_USER_MODEL='auth.CustomUserBadRequiredFields')
     def test_username_not_in_required_fields(self):
         "USERNAME_FIELD should not appear in REQUIRED_FIELDS."
         new_io = StringIO()
-        get_validation_errors(new_io, apps.get_app_config('auth').models_module)
+        get_validation_errors(new_io, apps.get_app_config('auth'))
         self.assertIn("The field named as the USERNAME_FIELD should not be included in REQUIRED_FIELDS on a swappable User model.", new_io.getvalue())
 
     @override_settings(AUTH_USER_MODEL='auth.CustomUserNonUniqueUsername')
     def test_username_non_unique(self):
         "A non-unique USERNAME_FIELD should raise a model validation error."
         new_io = StringIO()
-        get_validation_errors(new_io, apps.get_app_config('auth').models_module)
+        get_validation_errors(new_io, apps.get_app_config('auth'))
         self.assertIn("The USERNAME_FIELD must be unique. Add unique=True to the field parameters.", new_io.getvalue())
 
 
diff --git a/django/core/management/base.py b/django/core/management/base.py
index 59224049d2..413592a8f3 100644
--- a/django/core/management/base.py
+++ b/django/core/management/base.py
@@ -141,8 +141,8 @@ class BaseCommand(object):
         performed prior to executing the command. Default value is
         ``True``. To validate an individual application's models
         rather than all applications' models, call
-        ``self.validate(app)`` from ``handle()``, where ``app`` is the
-        application's Python module.
+        ``self.validate(app_config)`` from ``handle()``, where ``app_config``
+        is the application's configuration provided by the app registry.
 
     ``leave_locale_alone``
         A boolean indicating whether the locale set in settings should be
@@ -304,16 +304,16 @@ class BaseCommand(object):
             if saved_locale is not None:
                 translation.activate(saved_locale)
 
-    def validate(self, app=None, display_num_errors=False):
+    def validate(self, app_config=None, display_num_errors=False):
         """
         Validates the given app, raising CommandError for any errors.
 
-        If app is None, then this will validate all installed apps.
+        If app_config is None, then this will validate all installed apps.
 
         """
         from django.core.management.validation import get_validation_errors
         s = StringIO()
-        num_errors = get_validation_errors(s, app)
+        num_errors = get_validation_errors(s, app_config)
         if num_errors:
             s.seek(0)
             error_text = s.read()
diff --git a/django/core/management/validation.py b/django/core/management/validation.py
index 0af92bb5b7..e5eee65fef 100644
--- a/django/core/management/validation.py
+++ b/django/core/management/validation.py
@@ -20,7 +20,7 @@ class ModelErrorCollection:
         self.outfile.write(self.style.ERROR(force_str("%s: %s\n" % (context, error))))
 
 
-def get_validation_errors(outfile, app=None):
+def get_validation_errors(outfile, app_config=None):
     """
     Validates all models that are part of the specified app. If no app name is provided,
     validates all models of all installed apps. Writes errors, if any, to outfile.
@@ -32,7 +32,7 @@ def get_validation_errors(outfile, app=None):
 
     e = ModelErrorCollection(outfile)
 
-    for cls in apps.get_models(app, include_swapped=True):
+    for cls in (app_config or apps).get_models(include_swapped=True):
         opts = cls._meta
 
         # Check swappable attribute.
diff --git a/tests/invalid_models_tests/tests.py b/tests/invalid_models_tests/tests.py
index 2c98f39807..08cea2e15f 100644
--- a/tests/invalid_models_tests/tests.py
+++ b/tests/invalid_models_tests/tests.py
@@ -32,13 +32,13 @@ class InvalidModelTestCase(unittest.TestCase):
         TEST_SWAPPED_MODEL_BAD_MODEL='not_an_app.Target',
     )
     def test_invalid_models(self):
-        module = apps.get_app_config("invalid_models").models_module
-        get_validation_errors(self.stdout, module)
+        app_config = apps.get_app_config("invalid_models")
+        get_validation_errors(self.stdout, app_config)
 
         self.stdout.seek(0)
         error_log = self.stdout.read()
         actual = error_log.split('\n')
-        expected = module.model_errors.split('\n')
+        expected = app_config.models_module.model_errors.split('\n')
 
         unexpected = [err for err in actual if err not in expected]
         missing = [err for err in expected if err not in actual]