diff --git a/esptool/util.py b/esptool/util.py
index 91e4ee16b..ecd41c0d9 100644
--- a/esptool/util.py
+++ b/esptool/util.py
@@ -68,7 +68,7 @@ def print_overwrite(message, last_line=False):
     If output is not a TTY (for example redirected a pipe),
     no overwriting happens and this function is the same as print().
     """
-    if sys.stdout.isatty():
+    if hasattr(sys.stdout, "isatty") and sys.stdout.isatty():
         print("\r%s" % message, end="\n" if last_line else "")
     else:
         print(message)