diff --git a/packages/docusaurus-cssnano-preset/index.js b/packages/docusaurus-cssnano-preset/index.js
index 8c48b12fd5..924ede8bbd 100644
--- a/packages/docusaurus-cssnano-preset/index.js
+++ b/packages/docusaurus-cssnano-preset/index.js
@@ -6,14 +6,12 @@
  */
 
 const advancedBasePreset = require('cssnano-preset-advanced');
-const postCssCombineDuplicatedSelectors = require('postcss-combine-duplicated-selectors');
 const postCssSortMediaQueries = require('postcss-sort-media-queries');
 const postCssRemoveOverriddenCustomProperties = require('./src/remove-overridden-custom-properties');
 
 const preset = advancedBasePreset({autoprefixer: {add: true}});
 
 preset.plugins.unshift(
-  [postCssCombineDuplicatedSelectors, {removeDuplicatedValues: true}],
   [postCssSortMediaQueries],
   [postCssRemoveOverriddenCustomProperties],
 );
diff --git a/packages/docusaurus-cssnano-preset/package.json b/packages/docusaurus-cssnano-preset/package.json
index 3ea9656e00..900a08d213 100644
--- a/packages/docusaurus-cssnano-preset/package.json
+++ b/packages/docusaurus-cssnano-preset/package.json
@@ -15,7 +15,6 @@
   "dependencies": {
     "cssnano-preset-advanced": "^4.0.7",
     "postcss": "^7.0.2",
-    "postcss-combine-duplicated-selectors": "^9.1.0",
     "postcss-sort-media-queries": "^1.7.26"
   },
   "devDependencies": {
diff --git a/yarn.lock b/yarn.lock
index d93b171e30..76bcddeb65 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -15629,14 +15629,6 @@ postcss-colormin@^4.0.3:
     postcss "^7.0.0"
     postcss-value-parser "^3.0.0"
 
-postcss-combine-duplicated-selectors@^9.1.0:
-  version "9.4.0"
-  resolved "https://registry.yarnpkg.com/postcss-combine-duplicated-selectors/-/postcss-combine-duplicated-selectors-9.4.0.tgz#dae866debae5f93b58e13e6cc69419105e91336a"
-  integrity sha512-rMnO1H3wgR1T6QSlK3i8Slz9p3xD+0yOi4J7qwh/5PGR3z8jbgYvRlNKAIvXDtGBQbJKoWs4df5skL3a/fdUEA==
-  dependencies:
-    postcss "^7.0.0"
-    postcss-selector-parser "^6.0.0"
-
 postcss-convert-values@^4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/postcss-convert-values/-/postcss-convert-values-4.0.1.tgz#ca3813ed4da0f812f9d43703584e449ebe189a7f"
@@ -16200,7 +16192,7 @@ postcss-selector-parser@^5.0.0-rc.3, postcss-selector-parser@^5.0.0-rc.4:
     indexes-of "^1.0.1"
     uniq "^1.0.1"
 
-postcss-selector-parser@^6.0.0, postcss-selector-parser@^6.0.2, postcss-selector-parser@^6.0.4:
+postcss-selector-parser@^6.0.2, postcss-selector-parser@^6.0.4:
   version "6.0.4"
   resolved "https://registry.yarnpkg.com/postcss-selector-parser/-/postcss-selector-parser-6.0.4.tgz#56075a1380a04604c38b063ea7767a129af5c2b3"
   integrity sha512-gjMeXBempyInaBqpp8gODmwZ52WaYsVOsfr4L4lDQ7n3ncD6mEyySiDtgzCT+NYC0mmeOLvtsF8iaEf0YT6dBw==