diff --git a/odoo/netsvc.py b/odoo/netsvc.py
index 6de6e65ffbd..50c6d8bb124 100644
--- a/odoo/netsvc.py
+++ b/odoo/netsvc.py
@@ -25,6 +25,16 @@ def log(logger, level, prefix, msg, depth=None):
         logger.log(level, indent+line)
         indent=indent_after
 
+
+class WatchedFileHandler(logging.handlers.WatchedFileHandler):
+    def __init__(self, filename):
+        super().__init__(filename)
+        # Unfix bpo-26789, in case the fix is present
+        self._builtin_open = None
+
+    def _open(self):
+        return open(self.baseFilename, self.mode, encoding=self.encoding, errors=self.errors)
+
 class PostgreSQLHandler(logging.Handler):
     """ PostgreSQL Logging Handler will store logs in the database, by default
     the current database, can be set using --log-db=DBNAME
@@ -175,7 +185,7 @@ def init_logger():
             if dirname and not os.path.isdir(dirname):
                 os.makedirs(dirname)
             if os.name == 'posix':
-                handler = logging.handlers.WatchedFileHandler(logf)
+                handler = WatchedFileHandler(logf)
             else:
                 handler = logging.FileHandler(logf)
         except Exception: