diff --git a/IPython/core/interactiveshell.py b/IPython/core/interactiveshell.py
index 73ecc4a..ae26453 100644
--- a/IPython/core/interactiveshell.py
+++ b/IPython/core/interactiveshell.py
@@ -1704,7 +1704,7 @@ class InteractiveShell(SingletonConfigurable, Magic):
         [D:\ipython]|2> Hello Word_  # cursor is here        
         """
         if isinstance(s, unicode):
-            s = s.encode(self.stdin_encoding)
+            s = s.encode(self.stdin_encoding, 'replace')
         self.rl_next_input = s
 
     # Maybe move this to the terminal subclass?