diff --git a/scripts/dev/check_doc_changes.py b/scripts/dev/check_doc_changes.py
index ab879b5ac..7fc993283 100755
--- a/scripts/dev/check_doc_changes.py
+++ b/scripts/dev/check_doc_changes.py
@@ -39,4 +39,9 @@ if code != 0:
     print()
     print('(Or you have uncommitted changes, in which case you can ignore '
           'this.)')
+    if 'TRAVIS' in os.environ:
+        print()
+        print("travis_fold:start:gitdiff")
+        subprocess.call(['git', '--no-pager', 'diff'])
+        print("travis_fold:end:gitdiff")
 sys.exit(code)
diff --git a/tox.ini b/tox.ini
index 35bcb266c..2989fb1df 100644
--- a/tox.ini
+++ b/tox.ini
@@ -230,7 +230,7 @@ commands =
 [testenv:docs]
 basepython = python3
 whitelist_externals = git
-passenv = TRAVIS_PULL_REQUEST
+passenv = TRAVIS TRAVIS_PULL_REQUEST
 deps =
     -r{toxinidir}/requirements.txt
 commands =