diff --git a/.changeset/heavy-dots-sip.md b/.changeset/heavy-dots-sip.md
new file mode 100644
index 0000000000..2e0c4c29b1
--- /dev/null
+++ b/.changeset/heavy-dots-sip.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixed changes to vite configuration made in the astro:build:setup integration hook having no effect when target is "client"
diff --git a/packages/astro/src/core/build/static-build.ts b/packages/astro/src/core/build/static-build.ts
index 0535aaa7ac..935b4a2d5d 100644
--- a/packages/astro/src/core/build/static-build.ts
+++ b/packages/astro/src/core/build/static-build.ts
@@ -283,7 +283,7 @@ async function clientBuild(
 		base: settings.config.base,
 	};
 
-	await runHookBuildSetup({
+	const updatedViteBuildConfig = await runHookBuildSetup({
 		config: settings.config,
 		pages: internals.pagesByKeys,
 		vite: viteBuildConfig,
@@ -291,7 +291,7 @@ async function clientBuild(
 		logger: opts.logger,
 	});
 
-	const buildResult = await vite.build(viteBuildConfig);
+	const buildResult = await vite.build(updatedViteBuildConfig);
 	return buildResult;
 }