diff --git a/bin/oai-spec-validate-markdown b/bin/oai-spec-validate-markdown
index d18580e..05a0b9c 100755
--- a/bin/oai-spec-validate-markdown
+++ b/bin/oai-spec-validate-markdown
@@ -16,6 +16,7 @@ SPEC_CONFIG_LINT="${OAI_BUILD_INFRA_SPEC_CONFIG:-$PACKAGE_DIR/configs/markdownli
 LINKSPECTOR_CONFIG="${OAI_BUILD_INFRA_LINKSPECTOR_CONFIG:-.linkspector.yml}"
 MARKDOWNLINT="$(resolve_node_bin markdownlint-cli2 "$PACKAGE_DIR")"
 LINKSPECTOR="$(resolve_node_bin linkspector "$PACKAGE_DIR")"
+LINKSPECTOR_NODE_OPTIONS="${NODE_OPTIONS:-}"
 
 if [ ! -f "$CONFIG_FILE" ]; then
   echo "Error: $CONFIG_FILE not found"
@@ -32,5 +33,9 @@ fi
 "$MARKDOWNLINT" --config "$ROOT_CONFIG" "*.md"
 
 if [ -f "$LINKSPECTOR_CONFIG" ]; then
-  "$LINKSPECTOR" check --config "$LINKSPECTOR_CONFIG"
+  if [ "${OAI_BUILD_INFRA_LINKSPECTOR_NO_SANDBOX:-}" = "1" ] || { [ "${GITHUB_ACTIONS:-}" = "true" ] && [ "${OAI_BUILD_INFRA_LINKSPECTOR_NO_SANDBOX:-}" != "0" ]; }; then
+    LINKSPECTOR_NODE_OPTIONS="${LINKSPECTOR_NODE_OPTIONS:+$LINKSPECTOR_NODE_OPTIONS }--require $PACKAGE_DIR/src/shell/linkspector-no-sandbox.cjs"
+  fi
+
+  NODE_OPTIONS="$LINKSPECTOR_NODE_OPTIONS" "$LINKSPECTOR" check --config "$LINKSPECTOR_CONFIG"
 fi
diff --git a/src/shell/linkspector-no-sandbox.cjs b/src/shell/linkspector-no-sandbox.cjs
new file mode 100644
index 0000000..c846066
--- /dev/null
+++ b/src/shell/linkspector-no-sandbox.cjs
@@ -0,0 +1,10 @@
+// Linkspector adds Chromium's --no-sandbox flag when it detects a root user.
+// GitHub-hosted runners can also require --no-sandbox even when not running as
+// root, so this shim forces Linkspector down that existing launch path.
+if (typeof process.getuid === "function") {
+  Object.defineProperty(process, "getuid", {
+    value: () => 0,
+    configurable: true,
+    writable: true
+  });
+}
diff --git a/tests/shell/bin-resolution.test.mjs b/tests/shell/bin-resolution.test.mjs
index 33fe715..4405fe8 100644
--- a/tests/shell/bin-resolution.test.mjs
+++ b/tests/shell/bin-resolution.test.mjs
@@ -43,6 +43,51 @@ describe("shell command bin resolution", () => {
     expect(output).toContain("linkspector check --config");
   });
 
+  test("validate-markdown preloads the linkspector no-sandbox shim in GitHub Actions", () => {
+    const { consumer, installedPackage, consumerBin } = createInstalledPackageFixture();
+
+    writeFileSync(join(consumer, "README.md"), "# Fixture\n");
+    writeFileSync(join(consumer, ".linkspector.yml"), "dirs:\n  - .\n");
+    writeBin(join(consumerBin, "markdownlint-cli2"), "echo markdownlint \"$@\"");
+    writeBin(join(consumerBin, "linkspector"), "echo NODE_OPTIONS=\"$NODE_OPTIONS\"\necho linkspector \"$@\"");
+
+    const output = execFileSync("bash", [join(installedPackage, "bin/oai-spec-validate-markdown")], {
+      cwd: consumer,
+      encoding: "utf8",
+      env: {
+        ...process.env,
+        GITHUB_ACTIONS: "true",
+        PATH: `${consumerBin}:${process.env.PATH}`
+      }
+    });
+
+    expect(output).toContain("linkspector-no-sandbox.cjs");
+    expect(output).toContain("linkspector check --config");
+  });
+
+  test("validate-markdown can disable the linkspector no-sandbox shim", () => {
+    const { consumer, installedPackage, consumerBin } = createInstalledPackageFixture();
+
+    writeFileSync(join(consumer, "README.md"), "# Fixture\n");
+    writeFileSync(join(consumer, ".linkspector.yml"), "dirs:\n  - .\n");
+    writeBin(join(consumerBin, "markdownlint-cli2"), "echo markdownlint \"$@\"");
+    writeBin(join(consumerBin, "linkspector"), "echo NODE_OPTIONS=\"$NODE_OPTIONS\"\necho linkspector \"$@\"");
+
+    const output = execFileSync("bash", [join(installedPackage, "bin/oai-spec-validate-markdown")], {
+      cwd: consumer,
+      encoding: "utf8",
+      env: {
+        ...process.env,
+        GITHUB_ACTIONS: "true",
+        OAI_BUILD_INFRA_LINKSPECTOR_NO_SANDBOX: "0",
+        PATH: `${consumerBin}:${process.env.PATH}`
+      }
+    });
+
+    expect(output).not.toContain("linkspector-no-sandbox.cjs");
+    expect(output).toContain("linkspector check --config");
+  });
+
   test("validate-markdown skips linkspector when no linkspector config exists", () => {
     const { consumer, installedPackage, consumerBin } = createInstalledPackageFixture();