diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index a682562..936540e 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -73,6 +73,8 @@
 * ``post2000utctime.pem`` - Contains an RSA 2048 bit certificate with the
   ``notBefore`` and ``notAfter`` fields encoded as post-2000 ``UTCTime``.
 * ``dsa_root.pem`` - Contains a DSA root certificate generated using OpenSSL.
+* ``ec_no_named_curve.pem`` - Contains an ECDSA certificate that does not have
+  an embedded OID defining the curve.
 
 Hashes
 ~~~~~~
diff --git a/vectors/cryptography_vectors/x509/custom/ec_no_named_curve.pem b/vectors/cryptography_vectors/x509/custom/ec_no_named_curve.pem
new file mode 100644
index 0000000..4edeaa1
--- /dev/null
+++ b/vectors/cryptography_vectors/x509/custom/ec_no_named_curve.pem
@@ -0,0 +1,16 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----