diff --git a/src/inspector/JavaScriptRuntimeScope.ts b/src/inspector/JavaScriptRuntimeScope.ts
index 1bc51a13b0..16fe10d267 100644
--- a/src/inspector/JavaScriptRuntimeScope.ts
+++ b/src/inspector/JavaScriptRuntimeScope.ts
@@ -58,7 +58,7 @@ export const authorizeRuntimeLocation = async (
   asarHeaderAdmission: AsarHeaderAdmission = DEFAULT_ASAR_HEADER_ADMISSION,
 ): Promise<RuntimeLocationDecision> => {
   throwIfRuntimeObservationCancelled(signal, operation);
-  if (value.startsWith("file:")) {
+  if (URL.parse(value)?.protocol === "file:") {
     const filePath = await authorizedElectronFile(
       value,
       signal,
diff --git a/tests/acceptance/tools/inspectorFileUrlIdentity.test.ts b/tests/acceptance/tools/inspectorFileUrlIdentity.test.ts
new file mode 100644
index 0000000000..e36bc6659a
--- /dev/null
+++ b/tests/acceptance/tools/inspectorFileUrlIdentity.test.ts
@@ -0,0 +1,131 @@
+import { spawn } from "node:child_process";
+import { once } from "node:events";
+import { readFile, writeFile } from "node:fs/promises";
+import { join } from "node:path";
+import { pathToFileURL } from "node:url";
+import { expect, it, onTestFinished } from "vitest";
+
+import { toolContract } from "../../../src/contracts/toolContracts.js";
+import { connectLocalToolsMcp } from "../../fixtures/localToolsMcp.js";
+import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
+
+it("preserves file URL scheme spelling and script identity after real Inspector state changes", async () => {
+  const root = await createTestTempDirectory("rea-inspector-file-url-");
+  const source = join(root, "source #参数%.cjs");
+  const runner = join(root, "runner.cjs");
+  const sourceText = "globalThis.fileUrlProbe = true;\n";
+  await writeFile(source, sourceText);
+  await writeFile(
+    runner,
+    `
+    const { readFileSync } = require("node:fs");
+    const vm = require("node:vm");
+    const scripts = [];
+    process.on("message", (urls) => {
+      for (const filename of urls) {
+        const script = new vm.Script(readFileSync(process.argv[2], "utf8"), { filename });
+        scripts.push(script);
+        script.runInThisContext();
+      }
+      process.send({ loaded: scripts.length });
+    });
+    setInterval(() => {}, 1000);
+  `,
+  );
+  const child = spawn(
+    process.execPath,
+    ["--inspect=127.0.0.1:0", runner, source],
+    {
+      stdio: ["ignore", "ignore", "pipe", "ipc"],
+    },
+  );
+  onTestFinished(async () => {
+    if (child.exitCode === null && child.signalCode === null) {
+      const exited = once(child, "exit");
+      child.kill("SIGTERM");
+      await exited;
+    }
+  });
+  let stderr = "";
+  if (child.stderr === null) throw new Error("Expected piped Inspector stderr");
+  child.stderr.on("data", (chunk: Buffer) => {
+    stderr += chunk.toString();
+  });
+  const address = /ws:\/\/127\.0\.0\.1:\d+\/[^\s]+/u;
+  await expect.poll(() => stderr, { timeout: 5000 }).toMatch(address);
+  const socket = address.exec(stderr)?.[0];
+  if (socket === undefined) throw new Error("Node omitted its Inspector URL");
+  const endpoint = `http://127.0.0.1:${new URL(socket).port}`;
+  const load = async (urls: readonly string[]) => {
+    const loaded = once(child, "message");
+    child.send(urls);
+    await loaded;
+  };
+  const originalUrl = pathToFileURL(source).href;
+  await load([originalUrl]);
+  const { call } = await connectLocalToolsMcp();
+  const listed = await call("list_javascript_runtime_targets", {
+    inspector_endpoint: endpoint,
+  });
+  expect(listed.isError, JSON.stringify(listed.content)).not.toBe(true);
+  const discovery = toolContract(
+    "list_javascript_runtime_targets",
+  ).outputSchema.parse(listed.structuredContent);
+  const targetId = discovery.normalized_result.targets[0]?.target_id;
+  if (targetId === undefined) throw new Error("Node target was not listed");
+  const request = {
+    inspector_endpoint: endpoint,
+    target_id: targetId,
+    observation_ms: 25,
+  };
+  const observe = async () => {
+    const response = await call("observe_javascript_runtime", request);
+    expect(response.isError, JSON.stringify(response.content)).not.toBe(true);
+    return toolContract("observe_javascript_runtime").outputSchema.parse(
+      response.structuredContent,
+    );
+  };
+  const first = await observe();
+  const initialScript = first.normalized_result.scripts.items.find(
+    (script) => script.reported_url === originalUrl,
+  );
+  expect(initialScript).toMatchObject({
+    location: { kind: "file", file_path: source },
+  });
+
+  const addedUrls = [
+    originalUrl.replace(/^file:/u, "FILE:"),
+    `${originalUrl.replace(/^file:/u, "FiLe:")}?instance=2#selected`,
+    ` \t${originalUrl}\t `,
+  ];
+  await load(addedUrls);
+  const second = await observe();
+  const expectedUrls = [originalUrl, ...addedUrls];
+  const scripts = second.normalized_result.scripts.items.filter((script) =>
+    expectedUrls.includes(script.reported_url ?? ""),
+  );
+  expect(scripts.map((script) => script.reported_url)).toEqual(
+    expect.arrayContaining(expectedUrls),
+  );
+  expect(scripts).toHaveLength(4);
+  expect(new Set(scripts.map((script) => script.script_key)).size).toBe(4);
+  for (const script of scripts)
+    expect(script.location).toEqual({ kind: "file", file_path: source });
+  expect(
+    scripts.find((script) => script.reported_url === originalUrl)?.script_key,
+  ).toBe(initialScript?.script_key);
+
+  const retained = await call("get_evidence_bundle", {});
+  expect(retained.isError, JSON.stringify(retained.content)).not.toBe(true);
+  const records = toolContract("get_evidence_bundle").outputSchema.parse(
+    retained.structuredContent,
+  ).result.records;
+  const original = records.find(
+    (record) => record.evidence_id === first.evidence_id,
+  );
+  if (original === undefined || !("normalized_result" in original))
+    throw new Error("Original Inspector Evidence was not retained");
+  expect(original.predicate_type).toBe(first.predicate_type);
+  expect(original.normalized_result).toEqual(first.normalized_result);
+  expect(await readFile(source, "utf8")).toBe(sourceText);
+}, 30_000);