diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index 02cc122..5f0e198 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -203,6 +203,8 @@
 * ``cp_user_notice_no_explicit_text.pem`` - An RSA 2048 bit self-signed
   certificate containing a certificate policies extension with a user notice
   with no explicit text.
+* ``ian_uri.pem`` - An RSA 2048 bit certificate containing an issuer
+  alternative name extension with a ``URI`` general name.
 * ``ocsp_nocheck.pem`` - An RSA 2048 bit self-signed certificate containing
   an ``OCSPNoCheck`` extension.
 
diff --git a/vectors/cryptography_vectors/x509/custom/ian_uri.pem b/vectors/cryptography_vectors/x509/custom/ian_uri.pem
new file mode 100644
index 0000000..83b3ff5
--- /dev/null
+++ b/vectors/cryptography_vectors/x509/custom/ian_uri.pem
@@ -0,0 +1,19 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----