Issue #16244: Merged change from 3.2.
diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index 2918360..f286cd6 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -172,7 +172,6 @@
             if os.path.exists(dfn):
                 os.remove(dfn)
             self.rotate(self.baseFilename, dfn)
-        self.mode = 'w'
         self.stream = self._open()
 
     def shouldRollover(self, record):
@@ -381,7 +380,6 @@
         if self.backupCount > 0:
             for s in self.getFilesToDelete():
                 os.remove(s)
-        self.mode = 'w'
         self.stream = self._open()
         newRolloverAt = self.computeRollover(currentTime)
         while newRolloverAt <= currentTime: