diff --git a/packages/docusaurus/src/webpack/utils.ts b/packages/docusaurus/src/webpack/utils.ts
index a30faeca92d6..58f63c4fbae3 100644
--- a/packages/docusaurus/src/webpack/utils.ts
+++ b/packages/docusaurus/src/webpack/utils.ts
@@ -440,6 +440,7 @@ export function getMinimizer(useSimpleCssMinifier = false): Plugin[] {
               2: {
                 all: true,
                 restructureRules: true,
+                removeUnusedAtRules: false,
               },
             },
           },