diff --git a/.travis.yml b/.travis.yml
index a5987de..84c194e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -49,6 +49,8 @@ matrix:
     python: 3.5
   - env: TOXENV=py36-dj20
     python: 3.6
+  - env: TOXENV=py36-dj21
+    python: 3.6
   - env: TOXENV=py36-djmaster
     python: 3.6
   allow_failures:
diff --git a/configurations/importer.py b/configurations/importer.py
index 06b64fb..f9dfd6c 100644
--- a/configurations/importer.py
+++ b/configurations/importer.py
@@ -82,9 +82,16 @@ def name(self):
         return os.environ.get(self.namevar)
 
     def check_options(self):
-        parser = base.CommandParser(None,
-                                    usage="%(prog)s subcommand [options] [args]",
-                                    add_help=False)
+        try:
+            parser = base.CommandParser(
+                usage="%(prog)s subcommand [options] [args]",
+                add_help=False)
+        except TypeError:
+            # Django before 2.1 used a `cmd` argument.
+            parser = base.CommandParser(
+                None,
+                usage="%(prog)s subcommand [options] [args]",
+                add_help=False)
         parser.add_argument('--settings')
         parser.add_argument('--pythonpath')
         parser.add_argument(CONFIGURATION_ARGUMENT,
diff --git a/tox.ini b/tox.ini
index a367e6d..f48514a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,7 +8,8 @@ envlist =
     flake8-py36,
     readme-py27,
     py{27,34,35,36,py}-dj{18,110,111}
-    py{34,35,36}-dj{20,master}
+    py{34,35,36,37}-dj20
+    py{35,36,37}-dj{21,master}
 
 [testenv]
 usedevelop = true
@@ -21,6 +22,7 @@ deps =
     dj110: django>=1.10,<1.11
     dj111: django>=1.11,<2.0
     dj20: django>=2.0a1,<2.1
+    dj21: django>=2.1a1,<2.2
     djmaster: https://github.com/django/django/archive/master.tar.gz#egg=django
 
 commands =