diff --git a/packages/open-next/src/build/edge/createEdgeBundle.ts b/packages/open-next/src/build/edge/createEdgeBundle.ts
index b53177689..5ba1fe502 100644
--- a/packages/open-next/src/build/edge/createEdgeBundle.ts
+++ b/packages/open-next/src/build/edge/createEdgeBundle.ts
@@ -130,6 +130,27 @@ globalThis.Buffer = Buffer;
 
 import {AsyncLocalStorage} from "node:async_hooks";
 globalThis.AsyncLocalStorage = AsyncLocalStorage;
+
+${
+  ""
+  /**
+   * Next.js sets this `__import_unsupported` on `globalThis` (with `configurable: false`):
+   *  https://github.com/vercel/next.js/blob/5b7833e3/packages/next/src/server/web/globals.ts#L94-L98
+   *
+   * It does so in both the middleware and the main server, so if the middleware runs in the same place
+   * as the main handler this code gets run twice triggering a runtime error.
+   *
+   * For this reason we need to patch `Object.defineProperty` to avoid this issue.
+   */
+}
+const defaultDefineProperty = Object.defineProperty;
+Object.defineProperty = function(o, p, a) {
+  if(p=== '__import_unsupported' && Boolean(globalThis.__import_unsupported)) {
+    return;
+  }
+  return defaultDefineProperty(o, p, a);
+};
+
   ${
     isInCloudfare
       ? ""
@@ -137,14 +158,6 @@ globalThis.AsyncLocalStorage = AsyncLocalStorage;
   const require = (await import("node:module")).createRequire(import.meta.url);
   const __filename = (await import("node:url")).fileURLToPath(import.meta.url);
   const __dirname = (await import("node:path")).dirname(__filename);
-
-  const defaultDefineProperty = Object.defineProperty;
-  Object.defineProperty = function(o, p, a) {
-    if(p=== '__import_unsupported' && Boolean(globalThis.__import_unsupported)) {
-      return;
-    }
-    return defaultDefineProperty(o, p, a);
-  };
   `
   }
   ${additionalInject ?? ""}