diff --git a/libs/utils/logger/formatter.py b/libs/utils/logger/formatter.py
index c09f09d..dc04816 100644
--- a/libs/utils/logger/formatter.py
+++ b/libs/utils/logger/formatter.py
@@ -36,7 +36,7 @@ class BaseFormatter(Options):
     def format(self, message: LogMessage) -> str:
         raise NotImplementedError(f'{self.__class__.__name__}.format is not implemented')
 
-    def _format(self, message: LogMessage) -> str:
+    def _format(self, message: LogMessage) -> LogMessage:
         """
         Format message
         :param message:
@@ -44,6 +44,7 @@ class BaseFormatter(Options):
         """
         for formatter in self.sub_formatter:
             message = formatter._format(message)
+        return message
 
 
 class TimeFormatter(BaseFormatter):