diff --git a/core/nginx/config.py b/core/nginx/config.py
index 6f9123ad..94bb26b0 100755
--- a/core/nginx/config.py
+++ b/core/nginx/config.py
@@ -17,8 +17,8 @@ with open("/etc/resolv.conf") as handle:
     args["RESOLVER"] = f"[{resolver}]" if ":" in resolver else resolver
 
 # TLS configuration
-cert_name = os.getenv("TLS_CERT_FILENAME", default="cert.pem")
-keypair_name = os.getenv("TLS_KEYPAIR_FILENAME", default="key.pem")
+cert_name = args.get("TLS_CERT_FILENAME", "cert.pem")
+keypair_name = args.get("TLS_KEYPAIR_FILENAME", "key.pem")
 args["TLS"] = {
     "cert": ("/certs/%s" % cert_name, "/certs/%s" % keypair_name),
     "letsencrypt": ("/certs/letsencrypt/live/mailu/nginx-chain.pem",
@@ -36,7 +36,7 @@ def format_for_nginx(fullchain, output):
     split = '-----END CERTIFICATE-----\n'
     with open(fullchain, 'r') as pem:
         certs = [f'{cert}{split}' for cert in pem.read().split(split) if cert]
-    if len(certs)>2 and os.getenv('LETSENCRYPT_SHORTCHAIN'):
+    if len(certs)>2 and args.get('LETSENCRYPT_SHORTCHAIN'):
         del certs[-1]
     with open(output, 'w') as pem:
         pem.write(''.join(certs))