diff --git a/.travis.yml b/.travis.yml
index c92c78e..69a13a3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,9 +29,9 @@ matrix:
     - { python: 3.6, env: TOXENV=flake8 }
     - { python: 3.6, env: TOXENV=readme }
     # Work around Travis Python 3.7 issue: https://github.com/travis-ci/travis-ci/issues/9815
-    - { python: '3.7', env: DJANGO=1.11, dist: xenial, sudo: true }
-    - { python: '3.7', env: DJANGO=2.0, dist: xenial, sudo: true }
-    - { python: '3.7', env: DJANGO=2.1, dist: xenial, sudo: true }
+    - { python: 3.7, env: DJANGO=1.11, dist: xenial, sudo: true }
+    - { python: 3.7, env: DJANGO=2.0, dist: xenial, sudo: true }
+    - { python: 3.7, env: DJANGO=2.1, dist: xenial, sudo: true }
 
 install:
   - pip install tox-travis