diff --git a/.changeset/chilly-mayflies-float.md b/.changeset/chilly-mayflies-float.md
new file mode 100644
index 0000000000..dd0dfe1302
--- /dev/null
+++ b/.changeset/chilly-mayflies-float.md
@@ -0,0 +1,6 @@
+---
+"@utrecht/button-react": patch
+"@utrecht/calendar-react": patch
+---
+
+Fix missing bundled CSS for the React Button and Calendar components.
diff --git a/packages/component-library-react/rollup-component-package.mjs b/packages/component-library-react/rollup-component-package.mjs
index 8d25be8a9f..fb6fa1e817 100644
--- a/packages/component-library-react/rollup-component-package.mjs
+++ b/packages/component-library-react/rollup-component-package.mjs
@@ -61,7 +61,7 @@ export const createComponentPackageConfig = (path) => {
       ],
     },
     {
-      input: new URL('./src/index.tsx', path).pathname,
+      input: new URL('./src/css.tsx', path).pathname,
       output: [
         {
           file: 'dist/css.js',