diff --git a/pylxd/models/certificate.py b/pylxd/models/certificate.py
index eb616cf3..ec3daaf1 100644
--- a/pylxd/models/certificate.py
+++ b/pylxd/models/certificate.py
@@ -53,12 +53,13 @@ def all(cls, client):
     def create(
         cls,
         client,
-        secret,
+        password,
         cert_data,
         cert_type="client",
         name="",
         projects=None,
         restricted=False,
+        secret="",
     ):
         """Create a new certificate."""
         cert = x509.load_pem_x509_certificate(cert_data, default_backend())
@@ -73,9 +74,9 @@ def create(
             "projects": projects,
         }
         if client.has_api_extension("explicit_trust_token"):
-            data["trust_token"] = secret
+            data["trust_token"] = secret or password
         else:
-            data["password"] = secret
+            data["password"] = password
         response = client.api.certificates.post(json=data)
         location = response.headers["Location"]
         fingerprint = location.split("/")[-1]