diff --git a/build/gulpfile.extensions.ts b/build/gulpfile.extensions.ts
index e013781..3caf586 100644
--- a/build/gulpfile.extensions.ts
+++ b/build/gulpfile.extensions.ts
@@ -26,2 +26,3 @@ import * as util from './lib/util.ts';
 import watcher from './lib/watch/index.ts';
+import product from '../product.json' with { type: 'json' };
 
@@ -100,3 +101,3 @@ const compilations = [
 
-const getBaseUrl = (out: string) => `https://main.vscode-cdn.net/sourcemaps/${commit}/${out}`;
+const getBaseUrl = (out: string) => `https://github.com/VSCodium/sourcemaps/releases/download/${product.quality}-${commit}/extensions-${out.replaceAll('/', '-')}`;
 
diff --git a/build/gulpfile.reh.ts b/build/gulpfile.reh.ts
index 0ad08ab..78f17b8 100644
--- a/build/gulpfile.reh.ts
+++ b/build/gulpfile.reh.ts
@@ -494,3 +494,3 @@ function tweakProductForServerWeb(product: typeof import('../product.json')) {
 		util.rimraf(`out-vscode-${type}-min`),
-		optimize.minifyTask(`out-vscode-${type}`, `https://main.vscode-cdn.net/sourcemaps/${commit}/core`)
+		optimize.minifyTask(`out-vscode-${type}`, `https://github.com/VSCodium/sourcemaps/releases/download/${product.quality}-${commit}/core`)
 	));
diff --git a/build/gulpfile.vscode.ts b/build/gulpfile.vscode.ts
index 187726c..4854af5 100644
--- a/build/gulpfile.vscode.ts
+++ b/build/gulpfile.vscode.ts
@@ -238,3 +238,3 @@ function runTsGoTypeCheck(): Promise<void> {
 
-const sourceMappingURLBase = `https://main.vscode-cdn.net/sourcemaps/${commit}`;
+const sourceMappingURLBase = `https://github.com/VSCodium/sourcemaps/releases/download/${product.quality}-${commit}`;
 const isCI = !!process.env['CI'] || !!process.env['BUILD_ARTIFACTSTAGINGDIRECTORY'] || !!process.env['GITHUB_WORKSPACE'];
diff --git a/build/gulpfile.vscode.web.ts b/build/gulpfile.vscode.web.ts
index 3e6b29a..f031b99 100644
--- a/build/gulpfile.vscode.web.ts
+++ b/build/gulpfile.vscode.web.ts
@@ -164,3 +164,3 @@ const minifyVSCodeWebTask = task.define('minify-vscode-web-OLD', task.series(
 	util.rimraf('out-vscode-web-min'),
-	optimize.minifyTask('out-vscode-web', `https://main.vscode-cdn.net/sourcemaps/${commit}/core`)
+	optimize.minifyTask('out-vscode-web', `https://github.com/VSCodium/sourcemaps/releases/download/${product.quality}-${commit}/core`)
 ));
@@ -169,3 +169,3 @@ gulp.task(minifyVSCodeWebTask);
 // esbuild-based tasks (new)
-const sourceMappingURLBase = `https://main.vscode-cdn.net/sourcemaps/${commit}`;
+const sourceMappingURLBase = `https://github.com/VSCodium/sourcemaps/releases/download/${product.quality}-${commit}`;
 const esbuildBundleVSCodeWebTask = task.define('esbuild-vscode-web', () => runEsbuildBundle('out-vscode-web', false, true));
diff --git a/build/lib/extensions.ts b/build/lib/extensions.ts
index aacf25c..a62f2a7 100644
--- a/build/lib/extensions.ts
+++ b/build/lib/extensions.ts
@@ -32,4 +32,2 @@ const require = createRequire(import.meta.url);
 const root = path.dirname(path.dirname(import.meta.dirname));
-// const commit = getVersion(root);
-// const sourceMappingURLBase = `https://main.vscode-cdn.net/sourcemaps/${commit}`;
 
diff --git a/build/lib/optimize.ts b/build/lib/optimize.ts
index f5e812e..f9a4adc 100644
--- a/build/lib/optimize.ts
+++ b/build/lib/optimize.ts
@@ -229,3 +229,3 @@ export function bundleTask(opts: IBundleTaskOpts): () => NodeJS.ReadWriteStream
 export function minifyTask(src: string, sourceMapBaseUrl?: string): (cb: any) => void {
-	const sourceMappingURL = sourceMapBaseUrl ? ((f: any) => `${sourceMapBaseUrl}/${f.relative}.map`) : undefined;
+	const sourceMappingURL = sourceMapBaseUrl ? ((f: any) => `${sourceMapBaseUrl}-${f.relative.replaceAll('/', '-')}.map`) : undefined;
 	const target = getBuildTarget();
diff --git a/build/lib/util.ts b/build/lib/util.ts
index 4203e6e..a01fb78 100644
--- a/build/lib/util.ts
+++ b/build/lib/util.ts
@@ -287,4 +287,4 @@ export function rewriteSourceMappingURL(sourceMappingURLBase: string): NodeJS.Re
 			const contents = (f.contents as Buffer).toString('utf8');
-			const str = `//# sourceMappingURL=${sourceMappingURLBase}/${path.dirname(f.relative).replace(/\\/g, '/')}/$1`;
-			f.contents = Buffer.from(contents.replace(/\n\/\/# sourceMappingURL=(.*)$/gm, str));
+			const fp = path.dirname(f.relative).replace(/\\/g, '/').replaceAll('/', '-');
+			f.contents = Buffer.from(contents.replace(/\n\/\/# sourceMappingURL=(.*)$/gm, (_m, p) => `//# sourceMappingURL=${sourceMappingURLBase}/${fp}-${p.replaceAll('/', '-')}`));
 			return f;