diff --git a/packages/webpack/src/config/base.js b/packages/webpack/src/config/base.js
index 538a24580d..c8b090c0da 100644
--- a/packages/webpack/src/config/base.js
+++ b/packages/webpack/src/config/base.js
@@ -235,7 +235,7 @@ export default class WebpackBaseConfig {
         oneOf: styleLoader.apply('css')
       },
       {
-        test: /\.postcss$/,
+        test: /\.p(ost)?css$/,
         oneOf: styleLoader.apply('postcss')
       },
       {
diff --git a/test/fixtures/with-config/assets/app.css b/test/fixtures/with-config/assets/app.pcss
similarity index 100%
rename from test/fixtures/with-config/assets/app.css
rename to test/fixtures/with-config/assets/app.pcss
diff --git a/test/fixtures/with-config/nuxt.config.js b/test/fixtures/with-config/nuxt.config.js
index 2fc09622d1..670c6508bf 100644
--- a/test/fixtures/with-config/nuxt.config.js
+++ b/test/fixtures/with-config/nuxt.config.js
@@ -77,7 +77,7 @@ export default {
       })
     }
   },
-  css: [{ src: '~/assets/app.css' }],
+  css: [{ src: '~/assets/app.pcss' }],
   render: {
     csp: true,
     http2: {