diff --git a/.changeset/popular-melons-pretend.md b/.changeset/popular-melons-pretend.md
new file mode 100644
index 000000000000..60859e5f32f2
--- /dev/null
+++ b/.changeset/popular-melons-pretend.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/partytown': patch
+---
+
+fix partytown when base path specified
diff --git a/packages/integrations/partytown/src/index.ts b/packages/integrations/partytown/src/index.ts
index 44ffbe3106f7..eed0ab7c537e 100644
--- a/packages/integrations/partytown/src/index.ts
+++ b/packages/integrations/partytown/src/index.ts
@@ -36,7 +36,7 @@ export default function createPlugin(options: PartytownOptions): AstroIntegratio
 				config = _config;
 			},
 			'astro:server:setup': ({ server }) => {
-				const lib = `${config.base}~partytown/`;
+				const lib = `/~partytown/`;
 				server.middlewares.use(
 					sirv(partytownLibDirectory, {
 						mount: lib,