diff --git a/doc/common/conf.py b/doc/common/conf.py
index acc6f3d..018beb7 100644
--- a/doc/common/conf.py
+++ b/doc/common/conf.py
@@ -42,6 +42,10 @@ from pybricks._common import Speaker  # noqa E402
 # this line of code grabbed from docs.readthedocs.org
 ON_RTD = os.environ.get('READTHEDOCS', None) == 'True'
 
+# Since tags cannot be passed via SPHINXOPTS on read the docs, add it manually.
+if ON_RTD:
+    tags.add('main')
+
 _pyproject = toml.load(os.path.join(TOP_DIR, 'pyproject.toml'))
 
 # -- General configuration ------------------------------------------------