diff --git a/tests/pytest/util/dnodes.py b/tests/pytest/util/dnodes.py
index 51eed3d25a6d8e7f116b43d3d006198f695170e8..2532cec702df3dd8771721ac58dc750b202a8a36 100644
--- a/tests/pytest/util/dnodes.py
+++ b/tests/pytest/util/dnodes.py
@@ -69,7 +69,7 @@ class TDSimClient:
         self.cfg("numOfLogLines", "100000000")
         self.cfg("numOfThreadsPerCore", "2.0")
         self.cfg("locale", "en_US.UTF-8")
-        self.cfg("charset", "GBK")
+        self.cfg("charset", "UTF-8")
         self.cfg("asyncLog", "0")
         self.cfg("anyIp", "0")
         self.cfg("sdbDebugFlag", "135")