diff --git a/app/classes/shared/helpers.py b/app/classes/shared/helpers.py
index 9b5c8137..86bfe501 100644
--- a/app/classes/shared/helpers.py
+++ b/app/classes/shared/helpers.py
@@ -629,8 +629,8 @@ class Helpers:
         cert.get_subject().O = "Crafty Controller"
         cert.get_subject().OU = "Server Ops"
         cert.get_subject().CN = gethostname()
-        alt_names = ','.join([ 'DNS:%s' % socket.gethostname(), 'DNS:*.%s' % socket.gethostname(), 'DNS:localhost', 'DNS:*.localhost', 'DNS:127.0.0.1']).encode()
-        subjectAltNames_Ext = crypto.X509Extension(b'subjectAltName', False, ','.join([ 'DNS:%s' % socket.gethostname(), 'DNS:*.%s' % socket.gethostname(), 'DNS:localhost', 'DNS:*.localhost', 'DNS:127.0.0.1']).encode())
+        alt_names = ','.join([ f'DNS:{socket.gethostname()}', f'DNS:*.{socket.gethostname()}', 'DNS:localhost', 'DNS:*.localhost', 'DNS:127.0.0.1']).encode()
+        subjectAltNames_Ext = crypto.X509Extension(b'subjectAltName', False, alt_names)
         basicConstraints_Ext = crypto.X509Extension(b"basicConstraints", True, b"CA:false")
         cert.add_extensions([subjectAltNames_Ext, basicConstraints_Ext])
         cert.set_serial_number(random.randint(1,255))