diff --git a/tests/scripts/generate_tls13_compat_tests.py b/tests/scripts/generate_tls13_compat_tests.py
index 3d1754642..20dd8c4c5 100755
--- a/tests/scripts/generate_tls13_compat_tests.py
+++ b/tests/scripts/generate_tls13_compat_tests.py
@@ -349,27 +349,26 @@ class MbedTLSCli(TLSProgram):
         return ret
 
 
-SERVER_CLS = {'OpenSSL': OpenSSLServ, 'GnuTLS': GnuTLSServ}
-CLIENT_CLS = {'mbedTLS': MbedTLSCli}
+SERVER_CLASSES = {'OpenSSL': OpenSSLServ, 'GnuTLS': GnuTLSServ}
+CLIENT_CLASSES = {'mbedTLS': MbedTLSCli}
 
 
-def generate_compat_test(server=None, client=None, cipher=None,  # pylint: disable=unused-argument
-                         sig_alg=None, named_group=None, **kwargs):
+def generate_compat_test(server=None, client=None, cipher=None, sig_alg=None, named_group=None):
     """
     Generate test case with `ssl-opt.sh` format.
     """
     name = 'TLS 1.3 {client[0]}->{server[0]}: {cipher},{named_group},{sig_alg}'.format(
         client=client, server=server, cipher=cipher, sig_alg=sig_alg, named_group=named_group)
-    server = SERVER_CLS[server](cipher, sig_alg, named_group)
-    client = CLIENT_CLS[client](cipher, sig_alg, named_group)
+    server_object = SERVER_CLASSES[server](cipher, sig_alg, named_group)
+    client_object = CLIENT_CLASSES[client](cipher, sig_alg, named_group)
 
     cmd = ['run_test "{}"'.format(name), '"{}"'.format(
-        server.cmd()), '"{}"'.format(client.cmd()), '0']
-    cmd += server.post_checks()
-    cmd += client.post_checks()
+        server_object.cmd()), '"{}"'.format(client_object.cmd()), '0']
+    cmd += server_object.post_checks()
+    cmd += client_object.post_checks()
     prefix = ' \\\n' + (' '*9)
     cmd = prefix.join(cmd)
-    return '\n'.join(server.pre_checks() + client.pre_checks() + [cmd])
+    return '\n'.join(server_object.pre_checks() + client_object.pre_checks() + [cmd])
 
 
 SSL_OUTPUT_HEADER = '''#!/bin/sh
@@ -429,11 +428,11 @@ def main():
     parser.add_argument('--list-clients', action='store_true',
                         default=False, help='List supported TLS Clients')
 
-    parser.add_argument('server', choices=SERVER_CLS.keys(), nargs='?',
-                        default=list(SERVER_CLS.keys())[0],
+    parser.add_argument('server', choices=SERVER_CLASSES.keys(), nargs='?',
+                        default=list(SERVER_CLASSES.keys())[0],
                         help='Choose TLS server program for test')
-    parser.add_argument('client', choices=CLIENT_CLS.keys(), nargs='?',
-                        default=list(CLIENT_CLS.keys())[0],
+    parser.add_argument('client', choices=CLIENT_CLASSES.keys(), nargs='?',
+                        default=list(CLIENT_CLASSES.keys())[0],
                         help='Choose TLS client program for test')
     parser.add_argument('cipher', choices=CIPHER_SUITE_IANA_VALUE.keys(), nargs='?',
                         default=list(CIPHER_SUITE_IANA_VALUE.keys())[0],
@@ -448,16 +447,18 @@ def main():
     args = parser.parse_args()
 
     def get_all_test_cases():
-        for i in itertools.product(CIPHER_SUITE_IANA_VALUE.keys(), SIG_ALG_IANA_VALUE.keys(),
-                                   NAMED_GROUP_IANA_VALUE.keys(), SERVER_CLS.keys(),
-                                   CLIENT_CLS.keys()):
-            yield generate_compat_test(**dict(
-                zip(['cipher', 'sig_alg', 'named_group', 'server', 'client'], i)))
+        for cipher, sig_alg, named_group, server, client in \
+            itertools.product(CIPHER_SUITE_IANA_VALUE.keys(), SIG_ALG_IANA_VALUE.keys(),
+                              NAMED_GROUP_IANA_VALUE.keys(), SERVER_CLASSES.keys(),
+                              CLIENT_CLASSES.keys()):
+            yield generate_compat_test(cipher=cipher, sig_alg=sig_alg, named_group=named_group,
+                                       server=server, client=client)
 
     if args.generate_all_tls13_compat_tests:
         if args.output:
             with open(args.output, 'w', encoding="utf-8") as f:
-                f.write(SSL_OUTPUT_HEADER.format(filename=os.path.basename(args.output)))
+                f.write(SSL_OUTPUT_HEADER.format(
+                    filename=os.path.basename(args.output)))
                 f.write('\n\n'.join(get_all_test_cases()))
                 f.write('\n')
         else:
@@ -473,12 +474,13 @@ def main():
         if args.list_named_groups:
             print(*NAMED_GROUP_IANA_VALUE.keys())
         if args.list_servers:
-            print(*SERVER_CLS.keys())
+            print(*SERVER_CLASSES.keys())
         if args.list_clients:
-            print(*CLIENT_CLS.keys())
+            print(*CLIENT_CLASSES.keys())
         return 0
 
-    print(generate_compat_test(**vars(args)))
+    print(generate_compat_test(server=args.server, client=args.client,
+          sig_alg=args.sig_alg, cipher=args.cipher, named_group=args.named_group))
     return 0