diff --git a/vnpy/trader/engine.py b/vnpy/trader/engine.py
index a2e098ee..af136dab 100644
--- a/vnpy/trader/engine.py
+++ b/vnpy/trader/engine.py
@@ -197,13 +197,11 @@ class BaseEngine(ABC):
         pass
 
 
-class LogEngine(BaseEngine):
+class LogEngine(BaseEngine, metaclass=Singleton):
     """
     Processes log event and output with logging module.
     """
 
-    __metaclass__ = Singleton
-
     def __init__(self, main_engine: MainEngine, event_engine: EventEngine):
         """"""
         super(LogEngine, self).__init__(main_engine, event_engine, "log")
diff --git a/vnpy/trader/utility.py b/vnpy/trader/utility.py
index 9951e1f1..c221277a 100644
--- a/vnpy/trader/utility.py
+++ b/vnpy/trader/utility.py
@@ -14,10 +14,11 @@ from .object import BarData, TickData
 
 class Singleton(type):
     """
-    Singleton metaclass, 
+    Singleton metaclass,
 
-    class A:
-        __metaclass__ = Singleton
+    usage:
+    class A(metaclass=Singleton):
+        ...
     """
     _instances = {}