diff --git a/prestartup_script.py b/prestartup_script.py
index 22a0d082..47945f33 100644
--- a/prestartup_script.py
+++ b/prestartup_script.py
@@ -214,6 +214,9 @@ try:
                 # Handle error
                 raise ValueError("The object does not have a fileno method")
 
+        def isatty(self):
+            return False
+
         def write(self, message):
             global is_start_mode