diff --git a/.changeset/cyan-owls-tan.md b/.changeset/cyan-owls-tan.md
new file mode 100644
index 00000000..cbc05c8f
--- /dev/null
+++ b/.changeset/cyan-owls-tan.md
@@ -0,0 +1,5 @@
+---
+'ko': patch
+---
+
+optimize postcss-loader exclude
diff --git a/packages/ko/src/webpack/loaders/style.ts b/packages/ko/src/webpack/loaders/style.ts
index 55ebd821..d701de61 100644
--- a/packages/ko/src/webpack/loaders/style.ts
+++ b/packages/ko/src/webpack/loaders/style.ts
@@ -24,6 +24,12 @@ class Style {
       {
         test: /\.css$/,
         use: [this.styleLoader, this.cssLoader, this.postCSSLoader],
+        exclude: /node_modules/,
+      },
+      {
+        test: /\.css$/,
+        use: [this.styleLoader, this.cssLoader],
+        include: /node_modules/,
       },
       {
         test: /\.s[ac]ss$/,