diff --git a/aider/io.py b/aider/io.py
index fea95ac1f..925d60aac 100644
--- a/aider/io.py
+++ b/aider/io.py
@@ -13,7 +13,6 @@ from prompt_toolkit.key_binding import KeyBindings
 from prompt_toolkit.lexers import PygmentsLexer
 from prompt_toolkit.shortcuts import CompleteStyle, PromptSession
 from prompt_toolkit.styles import Style
-from prompt_toolkit.validation import Validator
 from pygments.lexers import MarkdownLexer, guess_lexer_for_filename
 from pygments.token import Token
 from pygments.util import ClassNotFound