diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index ff213ae87..76e7b2127 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -36,6 +36,7 @@ Fixes:
 - Add ``cython.final`` to leaf classes, ensuring that they are not subclassed.
 - Warn that ``CodecContext.decode()`` is not memory safe in some cases.
 - Fix ``enumerate_input_devices`` and ``enumerate_output_devices`` raising ``AttributeError`` (:issue:`2264`).
+- Map HTTP 429 to ``HTTPTooManyRequestsError`` instead of ``UndefinedError`` (:issue:`2267`).
 
 v17.0.1
 -------
diff --git a/av/error.py b/av/error.py
index 669c8e55a..e6cca095e 100644
--- a/av/error.py
+++ b/av/error.py
@@ -161,6 +161,7 @@ class HTTPClientError(FFmpegError):
     ("HTTP_UNAUTHORIZED", -lib.AVERROR_HTTP_UNAUTHORIZED, "HTTPUnauthorizedError", HTTPClientError),
     ("HTTP_FORBIDDEN", -lib.AVERROR_HTTP_FORBIDDEN, "HTTPForbiddenError", HTTPClientError),
     ("HTTP_NOT_FOUND", -lib.AVERROR_HTTP_NOT_FOUND, "HTTPNotFoundError", HTTPClientError),
+    ("HTTP_TOO_MANY_REQUESTS", -lib.AVERROR_HTTP_TOO_MANY_REQUESTS, "HTTPTooManyRequestsError", HTTPClientError),
     ("HTTP_OTHER_4XX", -lib.AVERROR_HTTP_OTHER_4XX, "HTTPOtherClientError", HTTPClientError),
     ("HTTP_SERVER_ERROR", -lib.AVERROR_HTTP_SERVER_ERROR, "HTTPServerError", HTTPError),
     ("PYAV_CALLBACK", c_PYAV_STASHED_ERROR, "PyAVCallbackError", RuntimeError),
diff --git a/av/error.pyi b/av/error.pyi
index c708a80f6..1191d962f 100644
--- a/av/error.pyi
+++ b/av/error.pyi
@@ -46,6 +46,7 @@ class HTTPBadRequestError(HTTPClientError): ...
 class HTTPUnauthorizedError(HTTPClientError): ...
 class HTTPForbiddenError(HTTPClientError): ...
 class HTTPNotFoundError(HTTPClientError): ...
+class HTTPTooManyRequestsError(HTTPClientError): ...
 class HTTPOtherClientError(HTTPClientError): ...
 class HTTPServerError(HTTPError): ...
 class PyAVCallbackError(FFmpegError, builtins.RuntimeError): ...
diff --git a/include/avutil.pxd b/include/avutil.pxd
index d7a1fb765..ede8f6fbe 100644
--- a/include/avutil.pxd
+++ b/include/avutil.pxd
@@ -172,6 +172,7 @@ cdef extern from "libavutil/error.h" nogil:
     cdef int AVERROR_HTTP_UNAUTHORIZED
     cdef int AVERROR_HTTP_FORBIDDEN
     cdef int AVERROR_HTTP_NOT_FOUND
+    cdef int AVERROR_HTTP_TOO_MANY_REQUESTS
     cdef int AVERROR_HTTP_OTHER_4XX
     cdef int AVERROR_HTTP_SERVER_ERROR
     cdef int AV_ERROR_MAX_STRING_SIZE
diff --git a/tests/test_errors.py b/tests/test_errors.py
index fdfe0f49d..f4dbf8fbc 100644
--- a/tests/test_errors.py
+++ b/tests/test_errors.py
@@ -63,3 +63,16 @@ def test_buffertoosmall() -> None:
         assert e.errno == BUFFER_TOO_SMALL
     else:
         assert False, "No exception raised!"
+
+
+def test_http_too_many_requests() -> None:
+    """HTTP 429 maps to HTTPTooManyRequestsError, not UndefinedError."""
+
+    HTTP_TOO_MANY_REQUESTS = av.error.tag_to_code(b"\xf8429")
+    try:
+        av.error.err_check(-HTTP_TOO_MANY_REQUESTS)
+    except av.error.HTTPTooManyRequestsError as e:
+        assert e.errno == HTTP_TOO_MANY_REQUESTS
+        assert isinstance(e, av.error.HTTPClientError)
+    else:
+        assert False, "No exception raised!"