diff --git a/src/package.ts b/src/package.ts
index 6dac2581..cb5c0708 100644
--- a/src/package.ts
+++ b/src/package.ts
@@ -505,7 +505,7 @@ export class ManifestProcessor extends BaseProcessor {
 			if (!minEngineVersion) {
 				throw new Error('Failed to get minVersion of engines.vscode')
 			}
-			
+
 			if (target) {
 				if (engineSemver.version !== 'latest' && !semver.satisfies(minEngineVersion, '>=1.61', { includePrerelease: true })) {
 					throw new Error(
@@ -1804,12 +1804,20 @@ function writeVsix(files: IFile[], packagePath: string): Promise<void> {
 			() =>
 				new Promise((c, e) => {
 					const zip = new yazl.ZipFile();
+					const zipOptions: Partial<yazl.Options> = {};
+
+					// reproducible zip files
+					const sde = process.env.SOURCE_DATE_EPOCH;
+					if (sde) {
+						const epoch = parseInt(sde);
+						zipOptions.mtime = new Date(epoch * 1000);
+						files = files.sort((a, b) => a.path.localeCompare(b.path))
+					}
+
 					files.forEach(f =>
 						isInMemoryFile(f)
-							? zip.addBuffer(typeof f.contents === 'string' ? Buffer.from(f.contents, 'utf8') : f.contents, f.path, {
-								mode: f.mode,
-							})
-							: zip.addFile(f.localPath, f.path, { mode: f.mode })
+							? zip.addBuffer(typeof f.contents === 'string' ? Buffer.from(f.contents, 'utf8') : f.contents, f.path, { ...zipOptions, mode: f.mode })
+							: zip.addFile(f.localPath, f.path, { ...zipOptions, mode: f.mode })
 					);
 					zip.end();
 
diff --git a/src/test/package.test.ts b/src/test/package.test.ts
index 467850a7..6b01a159 100644
--- a/src/test/package.test.ts
+++ b/src/test/package.test.ts
@@ -14,7 +14,7 @@ import {
 	versionBump,
 	VSIX,
 	LicenseProcessor,
-	printAndValidatePackagedFiles,
+	printAndValidatePackagedFiles, pack
 } from '../package';
 import { ManifestPackage } from '../manifest';
 import * as path from 'path';
@@ -2286,13 +2286,13 @@ describe('ManifestProcessor', () => {
 	});
 
 	it('should not throw error for engine version with x (e.g. 1.95.x)', async () => {
-        const root = fixture('uuid');
-        const manifest = JSON.parse(await fs.promises.readFile(path.join(root, 'package.json'), 'utf8'));
-        manifest.engines.vscode = '1.95.x';  // Non-strict semver, but acceptable
+		const root = fixture('uuid');
+		const manifest = JSON.parse(await fs.promises.readFile(path.join(root, 'package.json'), 'utf8'));
+		manifest.engines.vscode = '1.95.x';  // Non-strict semver, but acceptable
 
-        assert.doesNotThrow(() => new ManifestProcessor(manifest, { target: 'web' }));
-        assert.doesNotThrow(() => new ManifestProcessor(manifest, { preRelease: true }));
-    });
+		assert.doesNotThrow(() => new ManifestProcessor(manifest, { target: 'web' }));
+		assert.doesNotThrow(() => new ManifestProcessor(manifest, { preRelease: true }));
+	});
 });
 
 describe('MarkdownProcessor', () => {
@@ -3196,3 +3196,42 @@ describe('version', function () {
 		assert.strictEqual(newManifest.version, '1.0.0');
 	});
 });
+
+describe('writeVsix', function () {
+	this.timeout(60_000);
+
+	it('should be reproducible', async () => {
+		const exampleProject = fixture('manifestFiles');
+		const fixtureDir = fixture('');
+
+		const testDir = tmp.dirSync({ unsafeCleanup: true, tmpdir: fixtureDir });
+		const cwd = testDir.name
+
+		try {
+			fs.cpSync(exampleProject, cwd, { recursive: true });
+
+			const createVsix = async (vsixPath: string, epoch: number) => {
+				process.env["SOURCE_DATE_EPOCH"] = `${epoch}`;
+				await pack({ cwd, packagePath: vsixPath });
+			}
+
+			const vsix1 = testDir.name + '/vsix1.vsix';
+			const vsix2 = testDir.name + '/vsix2.vsix';
+			const vsix3 = testDir.name + '/vsix3.vsix';
+
+			await createVsix(vsix1, 1000000000);
+			await createVsix(vsix2, 1000000000);
+			await createVsix(vsix3, 1000000002);
+
+			const vsix1bytes = fs.readFileSync(vsix1);
+			const vsix2bytes = fs.readFileSync(vsix2);
+			const vsix3bytes = fs.readFileSync(vsix3);
+
+			assert.deepStrictEqual(vsix1bytes, vsix2bytes);
+			assert.notDeepStrictEqual(vsix1bytes, vsix3bytes);
+
+		} finally {
+			testDir.removeCallback();
+		}
+	});
+});