diff --git a/.changeset/fifty-parents-juggle.md b/.changeset/fifty-parents-juggle.md
new file mode 100644
index 00000000000..8087d52e1a3
--- /dev/null
+++ b/.changeset/fifty-parents-juggle.md
@@ -0,0 +1,5 @@
+---
+'@clerk/remix': patch
+---
+
+Fix RequestInit.duplex which now is required if body is provided in undici
diff --git a/packages/remix/src/ssr/authenticateRequest.ts b/packages/remix/src/ssr/authenticateRequest.ts
index 18457746852..27c23da94e2 100644
--- a/packages/remix/src/ssr/authenticateRequest.ts
+++ b/packages/remix/src/ssr/authenticateRequest.ts
@@ -3,6 +3,7 @@ import type { AuthenticateRequestOptions, SignedInState, SignedOutState } from '
 import { AuthStatus } from '@clerk/backend/internal';
 
 import type { LoaderFunctionArgs } from './types';
+import { patchRequest } from './utils';
 
 export async function authenticateRequest(
   args: LoaderFunctionArgs,
@@ -23,7 +24,7 @@ export async function authenticateRequest(
     domain,
     publishableKey,
     userAgent: `${PACKAGE_NAME}@${PACKAGE_VERSION}`,
-  }).authenticateRequest(request, {
+  }).authenticateRequest(patchRequest(request), {
     audience,
     authorizedParties,
     signInUrl,
diff --git a/packages/remix/src/ssr/loadOptions.ts b/packages/remix/src/ssr/loadOptions.ts
index 4753006d7d4..ea582305ebd 100644
--- a/packages/remix/src/ssr/loadOptions.ts
+++ b/packages/remix/src/ssr/loadOptions.ts
@@ -8,10 +8,11 @@ import { isTruthy } from '@clerk/shared/underscore';
 import { noSecretKeyError, satelliteAndMissingProxyUrlAndDomain, satelliteAndMissingSignInUrl } from '../utils/errors';
 import { getEnvVariable } from '../utils/utils';
 import type { LoaderFunctionArgs, RootAuthLoaderOptions } from './types';
+import { patchRequest } from './utils';
 
 export const loadOptions = (args: LoaderFunctionArgs, overrides: RootAuthLoaderOptions = {}) => {
   const { request, context } = args;
-  const clerkRequest = createClerkRequest(request);
+  const clerkRequest = createClerkRequest(patchRequest(request));
 
   // Fetch environment variables across Remix runtime.
   // 1. First check if the user passed the key in the getAuth function or the rootAuthLoader.
diff --git a/packages/remix/src/ssr/utils.ts b/packages/remix/src/ssr/utils.ts
index 5ac35891801..8ee504b4133 100644
--- a/packages/remix/src/ssr/utils.ts
+++ b/packages/remix/src/ssr/utils.ts
@@ -116,3 +116,18 @@ export function getResponseClerkState(requestState: RequestStateWithRedirectUrls
 export const wrapWithClerkState = (data: any) => {
   return { clerkState: { __internal_clerk_state: { ...data } } };
 };
+
+/**
+ * Patches request to avoid duplex issues with unidici
+ * For more information, see:
+ * https://github.com/nodejs/node/issues/46221
+ * https://github.com/whatwg/fetch/pull/1457
+ * @internal
+ */
+export const patchRequest = (request: Request) => {
+  const clonedRequest = request.clone();
+  if (clonedRequest.method !== 'GET' && clonedRequest.body !== null) {
+    (clonedRequest as unknown as { duplex: 'half' }).duplex = 'half';
+  }
+  return clonedRequest;
+};