diff --git a/package.json b/package.json
index b7f6bed5..9f7a31f8 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
     "get-folder-size": "^4.0.0",
     "husky": "^8.0.3",
     "ioredis": "^5.3.2",
+    "iso-639-1": "^3.1.5",
     "js-levenshtein": "^1.1.6",
     "js-yaml": "^4.1.0",
     "minio": "^7.1.3",
diff --git a/src/crawler.ts b/src/crawler.ts
index 2b46b6b9..0311481d 100644
--- a/src/crawler.ts
+++ b/src/crawler.ts
@@ -592,7 +592,14 @@ export class Crawler {
   extraChromeArgs() {
     const args = [];
     if (this.params.lang) {
-      args.push(`--accept-lang=${this.params.lang}`);
+      if (this.params.profile) {
+        logger.warn(
+          "Ignoring --lang option with profile, using language configured in the profile",
+          { lang: this.params.lang },
+        );
+      } else {
+        args.push(`--accept-lang=${this.params.lang}`);
+      }
     }
     return args;
   }
diff --git a/src/util/argParser.ts b/src/util/argParser.ts
index eed6d935..c0564ec9 100644
--- a/src/util/argParser.ts
+++ b/src/util/argParser.ts
@@ -1,5 +1,6 @@
 import path from "path";
 import fs from "fs";
+import ISO6391 from "iso-639-1";
 
 import yaml from "js-yaml";
 import { KnownDevices as devices } from "puppeteer-core";
@@ -770,6 +771,12 @@ class ArgParser {
       argv.emulateDevice = { viewport: null };
     }
 
+    if (argv.lang) {
+      if (!ISO6391.validate(argv.lang)) {
+        logger.fatal("Invalid ISO-639-1 country code for --lang: " + argv.lang);
+      }
+    }
+
     if (argv.seedFile) {
       const urlSeedFile = fs.readFileSync(argv.seedFile, "utf8");
       const urlSeedFileList = urlSeedFile.split("\n");
diff --git a/tests/lang-code.test.js b/tests/lang-code.test.js
new file mode 100644
index 00000000..a99387fe
--- /dev/null
+++ b/tests/lang-code.test.js
@@ -0,0 +1,23 @@
+import { execSync } from "child_process";
+
+test("run crawl with invalid lang", () => {
+  let status = 0;
+  try {
+    execSync(`docker run --rm webrecorder/browsertrix-crawler crawl --url https://webrecorder.net/feed.xml --lang e --limit 1`);
+  } catch (e) {
+    status = e.status;
+  }
+  expect(status).toBe(17);
+});
+
+test("run crawl with valid lang", () => {
+  let status = 0;
+  try {
+    execSync(`docker run --rm webrecorder/browsertrix-crawler crawl --url https://webrecorder.net/feed.xml --lang en --limit 1`);
+  } catch (e) {
+    status = e.status;
+  }
+  expect(status).toBe(0);
+});
+
+
diff --git a/yarn.lock b/yarn.lock
index 241134f0..014c7691 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3269,6 +3269,11 @@ isexe@^2.0.0:
   resolved "https://registry.yarnpkg.com/isexe/-/isexe-2.0.0.tgz#e8fbf374dc556ff8947a10dcb0572d633f2cfa10"
   integrity sha512-RHxMLp9lnKHGHRng9QFhRCMbYAcVpn69smSGcq3f36xjgVVWThj4qqLbTLlq7Ssj8B+fIQ1EuCEGI2lKsyQeIw==
 
+iso-639-1@^3.1.5:
+  version "3.1.5"
+  resolved "https://registry.yarnpkg.com/iso-639-1/-/iso-639-1-3.1.5.tgz#e8205aceeeea0f64d6b12f5fac6a943b0d5b452c"
+  integrity sha512-gXkz5+KN7HrG0Q5UGqSMO2qB9AsbEeyLP54kF1YrMsIxmu+g4BdB7rflReZTSTZGpfj8wywu6pfPBCylPIzGQA==
+
 istanbul-lib-coverage@^3.0.0, istanbul-lib-coverage@^3.2.0:
   version "3.2.2"
   resolved "https://registry.yarnpkg.com/istanbul-lib-coverage/-/istanbul-lib-coverage-3.2.2.tgz#2d166c4b0644d43a39f04bf6c2edd1e585f31756"