diff --git a/Lib/StringIO.py b/Lib/StringIO.py
index 2aef3c329e1..cb7313d42a9 100644
--- a/Lib/StringIO.py
+++ b/Lib/StringIO.py
@@ -45,6 +45,9 @@ class StringIO:
         self.closed = 0
         self.softspace = 0
 
+    def __iter__(self):
+        return iter(self.readline, '')
+
     def close(self):
         if not self.closed:
             self.closed = 1