diff --git a/src/instrumentation-node.ts b/src/instrumentation-node.ts
index b3f885c93f..31fe0b4099 100755
--- a/src/instrumentation-node.ts
+++ b/src/instrumentation-node.ts
@@ -7,6 +7,7 @@
  */
 
 import { markServerReady, markServerStarting } from "@/lib/serverLifecycle";
+import { normalizeBootError } from "@/lib/instrumentationBootError";
 
 function getRandomBytes(byteLength: number): Uint8Array {
   const bytes = new Uint8Array(byteLength);
@@ -37,23 +38,13 @@ export function renameProcessTitle(currentTitle: string): string {
   return `omniroute${currentTitle.slice("next-server".length)}`;
 }
 
-/**
- * Normalize any thrown/rejected value into a real `Error` instance.
- *
- * Next.js's own `registerInstrumentation()` wrapper (see
- * `node_modules/next/dist/server/lib/router-utils/instrumentation-globals.external.js`)
- * unconditionally does `err.message = \`...${err.message}\`` on whatever our
- * `register()` export rejects with, assuming it is always an `Error`. If a raw
- * non-Error primitive bubbles up instead (e.g. sql.js's WASM adapter throws the
- * bare string `"Database closed"` — see `./lib/db/adapters/sqljsAdapter.ts`),
- * that assignment throws `TypeError: Cannot create property 'message' on
- * string '...'` in strict mode, masking the original error and crashing the
- * whole server on every boot (#6560). Normalizing before it leaves our code
- * guarantees Next always receives something `.message`-assignable.
- */
-export function normalizeBootError(err: unknown): Error {
-  return err instanceof Error ? err : new Error(String(err));
-}
+// `normalizeBootError` now lives in `@/lib/instrumentationBootError` (imported
+// above) — shared, dependency-free, and reused by `src/instrumentation.ts`'s
+// outermost boot boundary (#10171) so both boot-failure logging sites agree
+// on the same normalization instead of maintaining two copies of the same
+// one-liner. Re-exported here so existing callers/tests importing it from
+// this module keep working unchanged.
+export { normalizeBootError };
 
 // Matches sql.js's raw `throw "Database closed"` (and similarly-worded
 // variants) thrown when a query runs against an already-closed WASM handle —
diff --git a/src/instrumentation.ts b/src/instrumentation.ts
index f0e6d41ce6..59270c7a2d 100644
--- a/src/instrumentation.ts
+++ b/src/instrumentation.ts
@@ -8,6 +8,8 @@
  * @see https://nextjs.org/docs/app/building-your-application/optimizing/instrumentation
  */
 
+import { normalizeBootError } from "@/lib/instrumentationBootError";
+
 /**
  * `registerNodejsFn` is only for tests to inject a fake without module-mocking
  * (`node:test` does not support `mock.module` reliably here) — mirrors the
@@ -34,7 +36,12 @@ export async function register(registerNodejsFn?: () => Promise<void>) {
       // up while every DB-touching route 500s forever with a permanently
       // empty app.log. This guarantees stdout/app.log is never silently
       // empty on a failed boot, regardless of platform or which step threw.
-      const normalizedError = err instanceof Error ? err : new Error(String(err));
+      // Reuses the same normalizeBootError() helper as ensureDbReadyForBoot
+      // (./instrumentation-node) — imported from a dependency-free module so
+      // this file, which also loads under the Edge runtime, never has to pull
+      // in Node-only code (or risk a second failing dynamic import of
+      // ./instrumentation-node itself) just to normalize the caught value.
+      const normalizedError = normalizeBootError(err);
       const message = normalizedError.message;
       console.error("[STARTUP] Fatal: instrumentation hook failed during boot:", message);
       throw normalizedError;
diff --git a/src/lib/instrumentationBootError.ts b/src/lib/instrumentationBootError.ts
new file mode 100644
index 0000000000..9cbee2733e
--- /dev/null
+++ b/src/lib/instrumentationBootError.ts
@@ -0,0 +1,26 @@
+/**
+ * Normalize any thrown/rejected value into a real `Error` instance.
+ *
+ * Next.js's own `registerInstrumentation()` wrapper (see
+ * `node_modules/next/dist/server/lib/router-utils/instrumentation-globals.external.js`)
+ * unconditionally does `err.message = \`...${err.message}\`` on whatever our
+ * `register()` export (`src/instrumentation.ts`) rejects with, assuming it is
+ * always an `Error`. If a raw non-Error primitive bubbles up instead (e.g.
+ * sql.js's WASM adapter throws the bare string `"Database closed"` — see
+ * `./db/adapters/sqljsAdapter.ts`), that assignment throws `TypeError: Cannot
+ * create property 'message' on string '...'` in strict mode, masking the
+ * original error and crashing the whole server on every boot (#6560).
+ * Normalizing before it leaves our code guarantees Next always receives
+ * something `.message`-assignable.
+ *
+ * Deliberately dependency-free (no imports) so both `src/instrumentation.ts`
+ * (the shared Edge+Node instrumentation entry point) and
+ * `src/instrumentation-node.ts` (the Node-only boot sequence) can import it
+ * statically without pulling Node-specific modules (fs/path/os/better-sqlite3
+ * etc.) into the Edge runtime bundle, and without relying on a dynamic
+ * `import("./instrumentation-node")` that could itself be the thing that
+ * failed to load (#10171).
+ */
+export function normalizeBootError(err: unknown): Error {
+  return err instanceof Error ? err : new Error(String(err));
+}