diff --git a/admin_interface/settings.py b/admin_interface/settings.py
index 91bc12a..d4ac7f1 100644
--- a/admin_interface/settings.py
+++ b/admin_interface/settings.py
@@ -5,33 +5,27 @@ from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 
 
+def check_installed_app(app, app_dj_version_limit):
+    dj_version = django.VERSION
+    installed_apps = settings.INSTALLED_APPS
+    if dj_version < app_dj_version_limit:
+        if app not in installed_apps:
+            raise ImproperlyConfigured(
+                '\'{}\' needed before django {}.{}, '
+                'add it to settings.INSTALLED_APPS.'.format(
+                    app, *app_dj_version_limit))
+    else:
+        if app in installed_apps:
+            raise ImproperlyConfigured(
+                '\'{}\' not needed since django {}.{}, '
+                'remove it from settings.INSTALLED_APPS.'.format(
+                    app, *app_dj_version_limit))
+
+
 def check_installed_apps():
     dj_version = django.VERSION
     installed_apps = settings.INSTALLED_APPS
 
-    if 'colorfield' not in installed_apps:
-        raise ImproperlyConfigured(
-            '\'colorfield\' needed, '
-            'add it to settings.INSTALLED_APPS.')
-
-    if dj_version < (1, 9):
-        if 'flat' not in installed_apps:
-            raise ImproperlyConfigured(
-                '\'flat\' needed before django 1.9, '
-                'add it to settings.INSTALLED_APPS.')
-    else:
-        if 'flat' in installed_apps:
-            raise ImproperlyConfigured(
-                '\'flat\' not needed since django 1.9, '
-                'remove it from settings.INSTALLED_APPS.')
-
-    if dj_version < (2, 0):
-        if 'flat_responsive' not in installed_apps:
-            raise ImproperlyConfigured(
-                '\'flat_responsive\' needed before django 2.0, '
-                'add it to settings.INSTALLED_APPS.')
-    else:
-        if 'flat_responsive' in installed_apps:
-            raise ImproperlyConfigured(
-                '\'flat_responsive\' not needed since django 2.0, '
-                'remove it from settings.INSTALLED_APPS.')
+    check_installed_app('colorfield', (4, 0))
+    check_installed_app('flat', (1, 9))
+    check_installed_app('flat_responsive', (2, 0))