diff --git a/.changeset/bright-cooks-pay.md b/.changeset/bright-cooks-pay.md
new file mode 100644
index 000000000..01d8b5e34
--- /dev/null
+++ b/.changeset/bright-cooks-pay.md
@@ -0,0 +1,5 @@
+---
+'@vanilla-extract/next-plugin': patch
+---
+
+Fixes Next.js 13.5.x CSS output on Windows when using React Server Components
diff --git a/packages/next-plugin/src/index.ts b/packages/next-plugin/src/index.ts
index 3a67ac522..313982d02 100644
--- a/packages/next-plugin/src/index.ts
+++ b/packages/next-plugin/src/index.ts
@@ -115,9 +115,8 @@ export const createVanillaExtractPlugin = (
         dir,
         resolvedNextConfig.experimental?.appDir ?? false,
       );
-      const hasAppDir =
-        !!resolvedNextConfig.experimental?.appDir &&
-        !!(findPagesDirResult && findPagesDirResult.appDir);
+      // Skip nextConfig check since appDir is stable feature after Next.js 13.4
+      const hasAppDir = !!(findPagesDirResult && findPagesDirResult.appDir);
 
       const outputCss = hasAppDir
         ? // Always output css since Next.js App Router needs to collect Server CSS from React Server Components