diff --git a/py/selenium/webdriver/firefox/service.py b/py/selenium/webdriver/firefox/service.py
index 7e5989a29e5f9..bdf7f31da6ec9 100644
--- a/py/selenium/webdriver/firefox/service.py
+++ b/py/selenium/webdriver/firefox/service.py
@@ -44,7 +44,7 @@ def __init__(
             in the services' environment.
         """
         if log_path:
-            log_file = open(log_path, "w")
+            log_file = open(log_path, "a+")
 
         service.Service.__init__(
             self, executable_path, port=port, log_file=log_file, env=env)