diff --git a/Lib/idlelib/idle_test/test_run.py b/Lib/idlelib/idle_test/test_run.py
index 83ecbffa2a197e..8f9f6df863dab7 100644
--- a/Lib/idlelib/idle_test/test_run.py
+++ b/Lib/idlelib/idle_test/test_run.py
@@ -125,7 +125,7 @@ def test_misc(self):
         self.assertIsNone(f.newlines)
         self.assertEqual(f.name, '<stdin>')
         self.assertFalse(f.closed)
-        self.assertTrue(f.isatty())
+        self.assertFalse(f.isatty())
         self.assertTrue(f.readable())
         self.assertFalse(f.writable())
         self.assertFalse(f.seekable())
@@ -228,7 +228,7 @@ def test_misc(self):
         self.assertIsNone(f.newlines)
         self.assertEqual(f.name, '<stdout>')
         self.assertFalse(f.closed)
-        self.assertTrue(f.isatty())
+        self.assertFalse(f.isatty())
         self.assertFalse(f.readable())
         self.assertTrue(f.writable())
         self.assertFalse(f.seekable())
diff --git a/Lib/idlelib/run.py b/Lib/idlelib/run.py
index a30db99a619a93..de05cee25b6b9a 100644
--- a/Lib/idlelib/run.py
+++ b/Lib/idlelib/run.py
@@ -463,7 +463,7 @@ def name(self):
         return '<%s>' % self.tags
 
     def isatty(self):
-        return True
+        return False
 
 
 class StdOutputFile(StdioFile):