diff --git a/src/cryptography/hazmat/backends/openssl/x509.py b/src/cryptography/hazmat/backends/openssl/x509.py
index c15aeb0ed9a6c9c3763c0392ed0fd31d6e913875_c3JjL2NyeXB0b2dyYXBoeS9oYXptYXQvYmFja2VuZHMvb3BlbnNzbC94NTA5LnB5..43ba5c28f16bbb75807c5916e7cd4dbfe7a07438_c3JjL2NyeXB0b2dyYXBoeS9oYXptYXQvYmFja2VuZHMvb3BlbnNzbC94NTA5LnB5 100644
--- a/src/cryptography/hazmat/backends/openssl/x509.py
+++ b/src/cryptography/hazmat/backends/openssl/x509.py
@@ -55,6 +55,9 @@
     def __hash__(self):
         return hash(self.public_bytes(serialization.Encoding.DER))
 
+    def __deepcopy__(self, memo):
+        return self
+
     def fingerprint(self, algorithm):
         h = hashes.Hash(algorithm, self._backend)
         h.update(self.public_bytes(serialization.Encoding.DER))
diff --git a/tests/x509/test_x509.py b/tests/x509/test_x509.py
index c15aeb0ed9a6c9c3763c0392ed0fd31d6e913875_dGVzdHMveDUwOS90ZXN0X3g1MDkucHk=..43ba5c28f16bbb75807c5916e7cd4dbfe7a07438_dGVzdHMveDUwOS90ZXN0X3g1MDkucHk= 100644
--- a/tests/x509/test_x509.py
+++ b/tests/x509/test_x509.py
@@ -7,6 +7,7 @@
 
 import binascii
 import collections
+import copy
 import datetime
 import ipaddress
 import os
@@ -4807,6 +4808,14 @@
         assert cert.signature_hash_algorithm is None
         assert cert.signature_algorithm_oid == SignatureAlgorithmOID.ED25519
 
+    def test_deepcopy(self, backend):
+        cert = _load_cert(
+            os.path.join("x509", "ed25519", "root-ed25519.pem"),
+            x509.load_pem_x509_certificate,
+            backend
+        )
+        assert copy.deepcopy(cert) is cert
+
 
 @pytest.mark.supported(
     only_if=lambda backend: backend.ed448_supported(),