diff --git a/.changeset/tame-poems-walk.md b/.changeset/tame-poems-walk.md
new file mode 100644
index 000000000000..579f6c1bb44c
--- /dev/null
+++ b/.changeset/tame-poems-walk.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Allow binary data to be returned from api routes in SSG
diff --git a/packages/astro/src/core/build/generate.ts b/packages/astro/src/core/build/generate.ts
index f5f72dc5ab93..3b163611ae75 100644
--- a/packages/astro/src/core/build/generate.ts
+++ b/packages/astro/src/core/build/generate.ts
@@ -382,7 +382,7 @@ async function generatePath(
 		route: pageData.route,
 	});
 
-	let body: string;
+	let body: string | Uint8Array;
 	let encoding: BufferEncoding | undefined;
 	if (pageData.route.type === 'endpoint') {
 		const endpointHandler = mod as unknown as EndpointHandler;
@@ -392,7 +392,8 @@ async function generatePath(
 			throwIfRedirectNotAllowed(result.response, opts.settings.config);
 			// If there's no body, do nothing
 			if (!result.response.body) return;
-			body = await result.response.text();
+			const ab = await result.response.arrayBuffer();
+			body = new Uint8Array(ab);
 		} else {
 			body = result.body;
 			encoding = result.encoding;
diff --git a/packages/astro/test/api-routes.test.js b/packages/astro/test/api-routes.test.js
index ba229c095abf..2536ad18f843 100644
--- a/packages/astro/test/api-routes.test.js
+++ b/packages/astro/test/api-routes.test.js
@@ -41,4 +41,12 @@ describe('API routes', () => {
 			});
 		});
 	});
+
+	describe('Binary data', () => {
+		it('can be returned from a response', async () => {
+			const dat = await fixture.readFile('/binary.dat', null);
+			expect(dat.length).to.equal(1);
+			expect(dat[0]).to.equal(0xff);
+		});
+	});
 });
diff --git a/packages/astro/test/fixtures/api-routes/src/pages/binary.dat.ts b/packages/astro/test/fixtures/api-routes/src/pages/binary.dat.ts
new file mode 100644
index 000000000000..c735896335de
--- /dev/null
+++ b/packages/astro/test/fixtures/api-routes/src/pages/binary.dat.ts
@@ -0,0 +1,5 @@
+import type { APIRoute } from 'astro';
+
+export const get: APIRoute = async function () {
+  return new Response(new Uint8Array([0xff]));
+};
diff --git a/packages/astro/test/test-utils.js b/packages/astro/test/test-utils.js
index 27e4caa5ea9c..13d3aa00a87e 100644
--- a/packages/astro/test/test-utils.js
+++ b/packages/astro/test/test-utils.js
@@ -167,7 +167,7 @@ export async function loadFixture(inlineConfig) {
 		},
 		pathExists: (p) => fs.existsSync(new URL(p.replace(/^\//, ''), config.outDir)),
 		readFile: (filePath, encoding) =>
-			fs.promises.readFile(new URL(filePath.replace(/^\//, ''), config.outDir), encoding ?? 'utf8'),
+			fs.promises.readFile(new URL(filePath.replace(/^\//, ''), config.outDir), encoding === undefined ? 'utf8' : encoding),
 		readdir: (fp) => fs.promises.readdir(new URL(fp.replace(/^\//, ''), config.outDir)),
 		glob: (p) =>
 			fastGlob(p, {