4 files changed, 35 insertions, 0 deletions
diff --git a/.changeset/healthy-ears-compete.md b/.changeset/healthy-ears-compete.md
new file mode 100644
index 000000000..f55d8b1e1
--- /dev/null
+++ b/.changeset/healthy-ears-compete.md
@@ -0,0 +1,5 @@
+---
+'astro': minor
+---
+
+astro-island now correctly passes Uint8Array/Uint16Array/Uint32Array
diff --git a/packages/astro/src/runtime/server/astro-island.ts b/packages/astro/src/runtime/server/astro-island.ts
index 894392524..60db5b6b1 100644
--- a/packages/astro/src/runtime/server/astro-island.ts
+++ b/packages/astro/src/runtime/server/astro-island.ts
@@ -26,6 +26,9 @@ declare const Astro: {
 		5: (value) => new Set(JSON.parse(value, reviver)),
 		6: (value) => BigInt(value),
 		7: (value) => new URL(value),
+		8: (value) => new Uint8Array(JSON.parse(value)),
+		9: (value) => new Uint16Array(JSON.parse(value)),
+		10: (value) => new Uint32Array(JSON.parse(value)),
 	};
 
 	const reviver = (propKey: string, raw: string): any => {
diff --git a/packages/astro/src/runtime/server/serialize.ts b/packages/astro/src/runtime/server/serialize.ts
index 021c050da..140823600 100644
--- a/packages/astro/src/runtime/server/serialize.ts
+++ b/packages/astro/src/runtime/server/serialize.ts
@@ -11,6 +11,9 @@ const PROP_TYPE = {
 	Set: 5,
 	BigInt: 6,
 	URL: 7,
+	Uint8Array: 8,
+	Uint16Array: 9,
+	Uint32Array: 10,
 };
 
 function serializeArray(
@@ -85,6 +88,15 @@ function convertToSerializedForm(
 		case '[object Array]': {
 			return [PROP_TYPE.JSON, JSON.stringify(serializeArray(value, metadata, parents))];
 		}
+		case '[object Uint8Array]': {
+			return [PROP_TYPE.Uint8Array, JSON.stringify(Array.from(value as Uint8Array))];
+		}
+		case '[object Uint16Array]': {
+			return [PROP_TYPE.Uint16Array, JSON.stringify(Array.from(value as Uint16Array))];
+		}
+		case '[object Uint32Array]': {
+			return [PROP_TYPE.Uint32Array, JSON.stringify(Array.from(value as Uint32Array))];
+		}
 		default: {
 			if (value !== null && typeof value === 'object') {
 				return [PROP_TYPE.Value, serializeObject(value, metadata, parents)];
diff --git a/packages/astro/test/serialize.test.js b/packages/astro/test/serialize.test.js
index 0646edfd7..c3ff0e5bd 100644
--- a/packages/astro/test/serialize.test.js
+++ b/packages/astro/test/serialize.test.js
@@ -42,6 +42,21 @@ describe('serialize', () => {
 		const output = `{"a":[7,"https://example.com/"]}`;
 		expect(serializeProps(input)).to.equal(output);
 	});
+	it('serializes a Uint8Array', () => {
+		const input = { a: new Uint8Array([1,2,3]) };
+		const output = `{"a":[8,"[1,2,3]"]}`;
+		expect(serializeProps(input)).to.equal(output);
+	});
+	it('serializes a Uint16Array', () => {
+		const input = { a: new Uint16Array([1,2,3]) };
+		const output = `{"a":[9,"[1,2,3]"]}`;
+		expect(serializeProps(input)).to.equal(output);
+	});
+	it('serializes a Uint32Array', () => {
+		const input = { a: new Uint32Array([1,2,3]) };
+		const output = `{"a":[10,"[1,2,3]"]}`;
+		expect(serializeProps(input)).to.equal(output);
+	});
 	it('cannot serialize a cyclic reference', () => {
 		const a = {};
 		a.b = a;