diff --git a/test/crossrunner/test.py b/test/crossrunner/test.py
index 633e926..0e91284 100644
--- a/test/crossrunner/test.py
+++ b/test/crossrunner/test.py
@@ -66,11 +66,19 @@
             'abstract': ['--abstract-namespace', '--domain-socket=%s' % domain_socket_path(port)],
         }.get(socket, None)
 
+    def _transport_args(self, transport):
+        return {
+            'zlib': ['--zlib'],
+        }.get(transport, None)
+
     def build_command(self, port):
         cmd = copy.copy(self._base_command)
         args = copy.copy(self._extra_args2)
         args.append('--protocol=' + self.protocol)
         args.append('--transport=' + self.transport)
+        transport_args = self._transport_args(self.transport)
+        if transport_args:
+            args += transport_args
         socket_args = self._socket_args(self.socket, port)
         if socket_args:
             args += socket_args