diff --git a/setup.py b/setup.py
index ee5848eb6..3dbd12612 100644
--- a/setup.py
+++ b/setup.py
@@ -34,7 +34,7 @@
         'beautifulsoup4~=4.9',
         'django~=3.1',  # TOM Toolkit requires db math functions
         'djangorestframework~=3.12',
-        'django-bootstrap4~=3.0',
+        'django-bootstrap4>=3,<22',
         'django-contrib-comments~=2.0',  # Earlier version are incompatible with Django >= 3.0
         'django-crispy-forms~=1.11',
         'django-extensions~=3.1',