From 4db24d6a8786bddfd4d0378cb3777430b3c3827b Mon Sep 17 00:00:00 2001
From: Andrii Furmanets <furmanets.andriy@gmail.com>
Date: Sat, 9 May 2026 21:35:03 +0300
Subject: [PATCH] fix: track custom module preloads in module resources

---
 .../src/server/ReactFizzConfigDOM.js          |  2 +-
 .../src/__tests__/ReactDOMFloat-test.js       | 20 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js b/packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js
index 691e49e563fd..b273d9a89edb 100644
--- a/packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js
+++ b/packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js
@@ -6552,7 +6552,7 @@ function preloadModule(
           resumableState.moduleUnknownResources.hasOwnProperty(as);
         let resources;
         if (hasAsType) {
-          resources = resumableState.unknownResources[as];
+          resources = resumableState.moduleUnknownResources[as];
           if (resources.hasOwnProperty(key)) {
             // we can return if we already have this resource
             return;
diff --git a/packages/react-dom/src/__tests__/ReactDOMFloat-test.js b/packages/react-dom/src/__tests__/ReactDOMFloat-test.js
index 4207fa5e32e0..c3185a4590cc 100644
--- a/packages/react-dom/src/__tests__/ReactDOMFloat-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOMFloat-test.js
@@ -6532,6 +6532,26 @@ body {
       );
     });
 
+    it('preloads multiple modules with the same custom as value', async () => {
+      function App() {
+        ReactDOM.preloadModule('worker-a', {as: 'serviceworker'});
+        ReactDOM.preloadModule('worker-b', {as: 'serviceworker'});
+        return <div>hello</div>;
+      }
+
+      await act(() => {
+        renderToPipeableStream(<App />).pipe(writable);
+      });
+
+      expect(getMeaningfulChildren(document.body)).toEqual(
+        <div id="container">
+          <link rel="modulepreload" href="worker-a" as="serviceworker" />
+          <link rel="modulepreload" href="worker-b" as="serviceworker" />
+          <div>hello</div>
+        </div>,
+      );
+    });
+
     it('warns if you provide invalid arguments', async () => {
       function App() {
         ReactDOM.preloadModule();