diff --git a/scripts/dependency-ownership-surface-report.mjs b/scripts/dependency-ownership-surface-report.mjs
index 15146995eb6..3d99542e2b8 100644
--- a/scripts/dependency-ownership-surface-report.mjs
+++ b/scripts/dependency-ownership-surface-report.mjs
@@ -397,7 +397,15 @@ function printTextReport(report) {
   process.stdout.write(renderTextReport(report));
 }
 
-function parseArgs(argv) {
+function readArtifactPath(argv, index, optionName) {
+  const value = argv[index + 1];
+  if (value === undefined || value === "" || value.startsWith("--")) {
+    throw new Error(`${optionName} requires a value`);
+  }
+  return value;
+}
+
+export function parseArgs(argv) {
   const options = {
     asJson: false,
     check: false,
@@ -421,7 +429,8 @@ function parseArgs(argv) {
       continue;
     }
     if (arg === "--markdown") {
-      options.markdownPath = argv[++index];
+      options.markdownPath = readArtifactPath(argv, index, arg);
+      index += 1;
       continue;
     }
     throw new Error(`Unsupported argument: ${arg}`);
diff --git a/test/scripts/dependency-ownership-surface-report.test.ts b/test/scripts/dependency-ownership-surface-report.test.ts
index 6487268db7b..d3aec28d053 100644
--- a/test/scripts/dependency-ownership-surface-report.test.ts
+++ b/test/scripts/dependency-ownership-surface-report.test.ts
@@ -7,6 +7,7 @@ import {
   collectDependencyOwnershipSurfaceCheckErrors,
   collectDependencyOwnershipSurfaceReport,
   packageNameFromLockKey,
+  parseArgs,
   renderDependencyOwnershipSurfaceMarkdownReport,
 } from "../../scripts/dependency-ownership-surface-report.mjs";
 
@@ -37,6 +38,25 @@ describe("packageNameFromLockKey", () => {
   });
 });
 
+describe("parseArgs", () => {
+  it("rejects missing markdown artifact paths", () => {
+    expect(() => parseArgs(["--markdown"])).toThrow("--markdown requires a value");
+    expect(() => parseArgs(["--markdown", "--json"])).toThrow("--markdown requires a value");
+    expect(() => parseArgs(["--markdown", ""])).toThrow("--markdown requires a value");
+  });
+
+  it("keeps json as a boolean or optional artifact path", () => {
+    expect(parseArgs(["--json"])).toMatchObject({
+      asJson: true,
+      jsonPath: null,
+    });
+    expect(parseArgs(["--json", "report.json"])).toMatchObject({
+      asJson: true,
+      jsonPath: "report.json",
+    });
+  });
+});
+
 describe("collectDependencyOwnershipSurfaceReport", () => {
   it("reports root dependency reachability, install-surface packages, and ownership metadata gaps", () => {
     const repoRoot = makeTempRepo();