diff --git a/.changeset/assets-loader-posix-public-path.md b/.changeset/assets-loader-posix-public-path.md
new file mode 100644
index 000000000..32c73ba04
--- /dev/null
+++ b/.changeset/assets-loader-posix-public-path.md
@@ -0,0 +1,5 @@
+---
+"@callstack/repack": patch
+---
+
+Fix the assets loader failing on Windows. Public paths for both remote and extracted assets were joined with `path.join`, which rewrites the separators to backslashes on Windows; for remote assets that turned `https://…` into a string `new URL` rejects, so any bundle containing a remote asset failed with `TypeError: Invalid URL`. Both are URLs rather than filesystem paths and are now joined with `path.posix.join`, which produces the same output on Linux and macOS as before.
diff --git a/packages/repack/src/loaders/assetsLoader/__tests__/windowsPaths.test.ts b/packages/repack/src/loaders/assetsLoader/__tests__/windowsPaths.test.ts
new file mode 100644
index 000000000..2d474228f
--- /dev/null
+++ b/packages/repack/src/loaders/assetsLoader/__tests__/windowsPaths.test.ts
@@ -0,0 +1,71 @@
+import path from 'node:path';
+import { convertToRemoteAssets } from '../convertToRemoteAssets.js';
+import { extractAssets } from '../extractAssets.js';
+import type { Asset } from '../types.js';
+
+// Run the loader helpers with Windows path semantics: `path.join` uses
+// backslashes, while `path.posix` stays available as it is on Windows.
+jest.mock('node:path', () => {
+  const { win32 } = jest.requireActual<typeof import('node:path')>('node:path');
+  return { __esModule: true, default: win32, ...win32 };
+});
+
+const pathSeparatorRegexp = new RegExp(`\\${path.sep}`, 'g');
+
+const assets: Asset[] = [
+  { data: Buffer.from(''), dimensions: null, filename: 'logo.png', scale: 1 },
+];
+
+describe('assets loader public paths on Windows', () => {
+  it.each([
+    [
+      'http://localhost:9999',
+      'src\\img',
+      'http://localhost:9999/assets/src/img',
+    ],
+    [
+      'https://cdn.example.com/assets/',
+      'node_modules\\pkg\\img',
+      'https://cdn.example.com/assets/assets/node_modules/pkg/img',
+    ],
+  ])(
+    'builds a valid remote URL from %s',
+    (remotePublicPath, resourceDirname, expected) => {
+      const code = convertToRemoteAssets({
+        assets,
+        assetsDirname: 'assets',
+        remotePublicPath,
+        resourceDirname,
+        resourceExtensionType: 'png',
+        resourceFilename: 'logo',
+        resourcePath: 'logo.png',
+        suffixPattern: '',
+        pathSeparatorRegexp,
+      });
+
+      expect(code).toContain(`"httpServerLocation":"${expected}"`);
+    }
+  );
+
+  it.each([
+    [undefined, 'assets/src/img'],
+    ['/public', '/public/assets/src/img'],
+  ])('joins publicPath %s with forward slashes', (publicPath, expected) => {
+    const code = extractAssets(
+      {
+        resourcePath: 'logo.png',
+        resourceDirname: 'src\\img',
+        resourceFilename: 'logo',
+        resourceExtensionType: 'png',
+        assets,
+        suffixPattern: '',
+        assetsDirname: 'assets',
+        pathSeparatorRegexp,
+        publicPath,
+      },
+      { debug: () => {} }
+    );
+
+    expect(code).toContain(`httpServerLocation: "${expected}"`);
+  });
+});
diff --git a/packages/repack/src/loaders/assetsLoader/convertToRemoteAssets.ts b/packages/repack/src/loaders/assetsLoader/convertToRemoteAssets.ts
index 3b3b08572..b8e95f1a4 100644
--- a/packages/repack/src/loaders/assetsLoader/convertToRemoteAssets.ts
+++ b/packages/repack/src/loaders/assetsLoader/convertToRemoteAssets.ts
@@ -26,8 +26,10 @@ export function convertToRemoteAssets({
     .join(assetsDirname, resourceDirname)
     .replace(pathSeparatorRegexp, '/');
 
-  // works on both unix & windows
-  const publicPathURL = new URL(path.join(remotePublicPath, assetPath));
+  // `remotePublicPath` is a URL, not a filesystem path, so it is joined with
+  // `path.posix` — `path.join` would rewrite the separators on Windows and
+  // produce something `new URL` rejects.
+  const publicPathURL = new URL(path.posix.join(remotePublicPath, assetPath));
 
   const size = getAssetSize(assets);
 
diff --git a/packages/repack/src/loaders/assetsLoader/extractAssets.ts b/packages/repack/src/loaders/assetsLoader/extractAssets.ts
index f50d91e80..665182c4d 100644
--- a/packages/repack/src/loaders/assetsLoader/extractAssets.ts
+++ b/packages/repack/src/loaders/assetsLoader/extractAssets.ts
@@ -36,7 +36,10 @@ export function extractAssets(
     .replace(pathSeparatorRegexp, '/');
 
   if (customPublicPath) {
-    publicPath = path.join(customPublicPath, publicPath);
+    // `publicPath` is served over HTTP and always uses forward slashes, so it
+    // is joined with `path.posix` regardless of the platform the bundle is
+    // built on.
+    publicPath = path.posix.join(customPublicPath, publicPath);
   }
 
   const size = getAssetSize(assets);