diff --git a/certbot_dns_transip/dns_transip.py b/certbot_dns_transip/dns_transip.py
index 81c1bf8..05e4687 100644
--- a/certbot_dns_transip/dns_transip.py
+++ b/certbot_dns_transip/dns_transip.py
@@ -41,7 +41,7 @@ class Authenticator(dns_common.DNSAuthenticator):
             "transip credentials INI file",
             {
                 "username": "Username for transip Remote API.",
-                "api-key": "Password for transip Remote API.",
+                "api-key-file": "Password for transip Remote API.",
             },
         )
 
@@ -67,5 +67,5 @@ class Authenticator(dns_common.DNSAuthenticator):
     def _get_transip_client(self):
         return DomainService(
             self.credentials.conf("username"),
-            self.credentials.conf("api-key"),
+            private_key_file=self.credentials.conf("api-key-file"),
         )