diff --git a/astro.config.mjs b/astro.config.mjs
index 1fd39a9..91bed24 100644
--- a/astro.config.mjs
+++ b/astro.config.mjs
@@ -6,6 +6,6 @@ import { defineConfig } from 'astro/config';
 
 // https://astro.build/config
 export default defineConfig({
-	site: process.env.SITE_URL ?? 'https://example.com',
+	site: process.env.SITE_URL || 'https://example.com',
 	integrations: [mdx(), sitemap()],
 });