diff --git a/.changeset/slow-plums-bake.md b/.changeset/slow-plums-bake.md
new file mode 100644
index 00000000..d2c64e13
--- /dev/null
+++ b/.changeset/slow-plums-bake.md
@@ -0,0 +1,5 @@
+---
+'playroom': patch
+---
+
+Restrict `playroom`'s Vanilla Extract plugin to only process playroom's `.css.ts` files
diff --git a/lib/makeWebpackConfig.js b/lib/makeWebpackConfig.js
index 0179abe9..3051fbf9 100644
--- a/lib/makeWebpackConfig.js
+++ b/lib/makeWebpackConfig.js
@@ -180,7 +180,15 @@ module.exports = async (playroomConfig, options) => {
         filename: 'preview/index.html',
         publicPath: '../',
       }),
-      new VanillaExtractPlugin(),
+      new VanillaExtractPlugin({
+        test: (filePath) => {
+          // Only apply VanillaExtract plugin to playroom's source `.css.ts` files
+          return (
+            /\.css\.ts$/i.test(filePath) &&
+            includePaths.some((includePath) => filePath.startsWith(includePath))
+          );
+        },
+      }),
       new MiniCssExtractPlugin({ ignoreOrder: true }),
       ...(options.production ? [] : [new FriendlyErrorsWebpackPlugin()]),
       // If using a version of React earlier than 18, ignore the