diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6b5c7379b..9ded24cff 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -3,6 +3,8 @@ jobs:
   build:
     docker:
       - image: sphinxdoc/docker-ci
+        environment:
+          DO_EPUBCHECK: 1
     working_directory: /sphinx
     steps:
       - checkout