diff --git a/doc/utils/sphinx-config/_themes/lammps_theme/static/css/lammps.css b/doc/utils/sphinx-config/_themes/lammps_theme/static/css/lammps.css
index b5637b389c..b9816c3f8c 100644
--- a/doc/utils/sphinx-config/_themes/lammps_theme/static/css/lammps.css
+++ b/doc/utils/sphinx-config/_themes/lammps_theme/static/css/lammps.css
@@ -3,3 +3,7 @@
     display: block;
     margin-bottom: 0.809em;
 }
+
+.versionmodified {
+    font-weight: bold;
+}