diff --git a/sros2/sros2/_utilities.py b/sros2/sros2/_utilities.py
index 080b447a..f35442f4 100644
--- a/sros2/sros2/_utilities.py
+++ b/sros2/sros2/_utilities.py
@@ -80,7 +80,7 @@ def build_key_and_cert(subject_name, *, ca=False, ca_key=None, issuer_name=''):
     else:
         extension = x509.BasicConstraints(ca=False, path_length=None)
 
-    utcnow = datetime.datetime.now(datetime.UTC)
+    utcnow = datetime.datetime.utcnow()
     builder = x509.CertificateBuilder(
         ).issuer_name(
             issuer_name
diff --git a/sros2/test/sros2/commands/security/verbs/test_create_enclave.py b/sros2/test/sros2/commands/security/verbs/test_create_enclave.py
index e790c3af..bed0c740 100644
--- a/sros2/test/sros2/commands/security/verbs/test_create_enclave.py
+++ b/sros2/test/sros2/commands/security/verbs/test_create_enclave.py
@@ -123,7 +123,7 @@ def test_cert_pem(enclave_keys_dir):
     assert isinstance(cert.signature_hash_algorithm, hashes.SHA256)
 
     # Verify the cert is valid for the expected timespan
-    utcnow = datetime.datetime.now(datetime.UTC)
+    utcnow = datetime.datetime.utcnow()
 
     # Using a day earlier here to prevent Connext (5.3.1) from complaining
     # when extracting it from the permissions file and thinking it's in the future