diff --git a/django/contrib/admin/sites.py b/django/contrib/admin/sites.py
index d056ef337c..b3297d04f6 100644
--- a/django/contrib/admin/sites.py
+++ b/django/contrib/admin/sites.py
@@ -2,7 +2,6 @@ from functools import update_wrapper
 from weakref import WeakSet
 
 from django.apps import apps
-from django.conf import settings
 from django.contrib.admin import ModelAdmin, actions
 from django.contrib.auth import REDIRECT_FIELD_NAME
 from django.core.exceptions import ImproperlyConfigured
@@ -71,9 +70,6 @@ class AdminSite(object):
         Run the system checks on all ModelAdmins, except if they aren't
         customized at all.
         """
-        if not settings.DEBUG:
-            return []
-
         if app_configs is None:
             app_configs = apps.get_app_configs()
         app_configs = set(app_configs)  # Speed up lookups below
diff --git a/tests/admin_checks/tests.py b/tests/admin_checks/tests.py
index d243a56640..3d629077c5 100644
--- a/tests/admin_checks/tests.py
+++ b/tests/admin_checks/tests.py
@@ -45,7 +45,6 @@ class MyAdmin(admin.ModelAdmin):
 )
 class SystemChecksTestCase(SimpleTestCase):
 
-    @override_settings(DEBUG=True)
     def test_checks_are_performed(self):
         admin.site.register(Song, MyAdmin)
         try:
@@ -93,7 +92,6 @@ class SystemChecksTestCase(SimpleTestCase):
         ]
         self.assertEqual(errors, expected)
 
-    @override_settings(DEBUG=True)
     def test_custom_adminsite(self):
         class CustomAdminSite(admin.AdminSite):
             pass
@@ -107,7 +105,6 @@ class SystemChecksTestCase(SimpleTestCase):
         finally:
             custom_site.unregister(Song)
 
-    @override_settings(DEBUG=True)
     def test_allows_checks_relying_on_other_modeladmins(self):
         class MyBookAdmin(admin.ModelAdmin):
             def check(self, **kwargs):