diff --git a/Lib/idlelib/PyShell.py b/Lib/idlelib/PyShell.py
index 0ee70d9f86b..5b920b20499 100644
--- a/Lib/idlelib/PyShell.py
+++ b/Lib/idlelib/PyShell.py
@@ -834,8 +834,8 @@ def get_standard_extension_names(self):
     closing = False
 
     def set_warning_stream(self, stream):
-	global warning_stream
-	warning_stream = stream
+        global warning_stream
+        warning_stream = stream
 
     def get_warning_stream(self):
         return warning_stream