diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py
index efd7b890004a..c982167e671b 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py
@@ -48,6 +48,7 @@ class GdbRemoteTestCaseBase(TestBase):
     _verbose_log_handler = None
     _log_formatter = logging.Formatter(fmt='%(asctime)-15s %(levelname)-8s %(message)s')
     _remote_server_log_file = None
+    debug_monitor_extra_args = []
 
     def setUpBaseLogging(self):
         self.logger = logging.getLogger(__name__)