diff --git a/lib/tools.js b/lib/tools.js
index 2cf72b74..fe648ea0 100644
--- a/lib/tools.js
+++ b/lib/tools.js
@@ -241,6 +241,13 @@ function formatTokenError(provider, tokenRequest) {
     return parts.join(': ');
 }
 
+function resolveOAuthErrorStatus(responseError, err) {
+    if (typeof responseError.code === 'number' && responseError.code >= 400) {
+        return responseError.code;
+    }
+    return (err && err.statusCode) || (err && err.oauthRequest && err.oauthRequest.status) || 500;
+}
+
 module.exports = {
     /**
      * Helper function to set specific bit in a buffer
@@ -1963,7 +1970,9 @@ MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEV3QUiYsp13nD9suD1/ZkEXnuMoSg
 
     normalizeHashKeys,
 
-    formatTokenError
+    formatTokenError,
+
+    resolveOAuthErrorStatus
 };
 
 function msgpackDecode(buf) {
diff --git a/test/oauth-error-status-test.js b/test/oauth-error-status-test.js
new file mode 100644
index 00000000..c5c99747
--- /dev/null
+++ b/test/oauth-error-status-test.js
@@ -0,0 +1,59 @@
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert').strict;
+
+const { resolveOAuthErrorStatus } = require('../lib/tools');
+
+test('resolveOAuthErrorStatus tests', async t => {
+    await t.test('returns numeric error code when it is a valid HTTP status', async () => {
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 400 }, {}), 400);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 403 }, {}), 403);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 404 }, {}), 404);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 429 }, {}), 429);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 500 }, {}), 500);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 503 }, {}), 503);
+    });
+
+    await t.test('falls back to err.statusCode when error code is a string', async () => {
+        let err = { statusCode: 429 };
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'TooManyPendingRequests' }, err), 429);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'TooManyRequests' }, err), 429);
+
+        err = { statusCode: 400 };
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'BadRequest' }, err), 400);
+    });
+
+    await t.test('falls back to err.oauthRequest.status when err.statusCode is missing', async () => {
+        let err = { oauthRequest: { status: 429 } };
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'TooManyPendingRequests' }, err), 429);
+
+        err = { oauthRequest: { status: 503 } };
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'ServiceUnavailable' }, err), 503);
+    });
+
+    await t.test('returns 500 when no fallback status is available', async () => {
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'UnknownError' }, {}), 500);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'TooManyPendingRequests' }, {}), 500);
+    });
+
+    await t.test('rejects numeric codes below 400', async () => {
+        let err = { statusCode: 429 };
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 200 }, err), 429);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 301 }, err), 429);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 0 }, err), 429);
+    });
+
+    await t.test('handles undefined and null error codes', async () => {
+        let err = { statusCode: 502 };
+        assert.strictEqual(resolveOAuthErrorStatus({ code: undefined }, err), 502);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: null }, err), 502);
+        assert.strictEqual(resolveOAuthErrorStatus({}, err), 502);
+    });
+
+    await t.test('handles missing err parameter', async () => {
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 403 }, null), 403);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'BadRequest' }, null), 500);
+        assert.strictEqual(resolveOAuthErrorStatus({ code: 'BadRequest' }, undefined), 500);
+    });
+});
diff --git a/workers/api.js b/workers/api.js
index 11761122..aa933fb8 100644
--- a/workers/api.js
+++ b/workers/api.js
@@ -40,7 +40,8 @@ const {
     getBoolean,
     loadTlsConfig,
     httpAgent,
-    reloadHttpProxyAgent
+    reloadHttpProxyAgent,
+    resolveOAuthErrorStatus
 } = require('../lib/tools');
 const { matchIp, detectAutomatedRequest } = require('../lib/utils/network');
 
@@ -2145,7 +2146,7 @@ Include your token in requests using one of these methods:
                                         message = response.error.message;
                                     }
 
-                                    let error = Boom.boomify(new Error(message), { statusCode: response.error.code });
+                                    let error = Boom.boomify(new Error(message), { statusCode: resolveOAuthErrorStatus(response.error, err) });
                                     throw error;
                                 }
                                 throw err;
@@ -2239,7 +2240,7 @@ Include your token in requests using one of these methods:
                             let response = err.oauthRequest && err.oauthRequest.response;
                             if (response && response.error) {
                                 let message = response.error.message;
-                                let error = Boom.boomify(new Error(message), { statusCode: response.error.code });
+                                let error = Boom.boomify(new Error(message), { statusCode: resolveOAuthErrorStatus(response.error, err) });
                                 throw error;
                             }
                             throw err;
@@ -2328,7 +2329,7 @@ Include your token in requests using one of these methods:
                         let response = err.oauthRequest && err.oauthRequest.response;
                         if (response && response.error) {
                             let message = response.error.message;
-                            let error = Boom.boomify(new Error(message), { statusCode: response.error.code });
+                            let error = Boom.boomify(new Error(message), { statusCode: resolveOAuthErrorStatus(response.error, err) });
                             throw error;
                         }
                         throw err;