diff --git a/tests/system-test/0-others/compatibility.py b/tests/system-test/0-others/compatibility.py
index b8623c3bcd..3fcff9b3de 100644
--- a/tests/system-test/0-others/compatibility.py
+++ b/tests/system-test/0-others/compatibility.py
@@ -151,10 +151,10 @@ class TDTestCase:
         os.system("LD_LIBRARY_PATH=/usr/lib  taos -s 'flush database db4096 '")
         os.system("LD_LIBRARY_PATH=/usr/lib  taos -f 0-others/TS-3131.tsql")
 
-        # cmd = f" LD_LIBRARY_PATH={bPath}/build/lib  {bPath}/build/bin/taos -h localhost ;"
-        # tdLog.info(f"new  client version  connect to old version taosd, commad return value:{cmd}")
-        # if os.system(cmd) == 0:
-        #     raise Exception("failed to execute system command. cmd: %s" % cmd)
+        cmd = f" LD_LIBRARY_PATH={bPath}/build/lib  {bPath}/build/bin/taos -h localhost ;"
+        tdLog.info(f"new  client version  connect to old version taosd, commad return value:{cmd}")
+        if os.system(cmd) == 0:
+            raise Exception("failed to execute system command. cmd: %s" % cmd)
                 
         os.system("pkill  taosd")   # make sure all the data are saved in disk.
         self.checkProcessPid("taosd")