diff --git a/aider/io.py b/aider/io.py
index f8cf78cd3..46621cfce 100644
--- a/aider/io.py
+++ b/aider/io.py
@@ -308,9 +308,11 @@ class InputOutput:
         self.yes = yes
 
         self.input_history_file = input_history_file
+        Path(self.input_history_file).parent.mkdir(parents=True, exist_ok=True)
         self.llm_history_file = llm_history_file
         if chat_history_file is not None:
             self.chat_history_file = Path(chat_history_file)
+            self.chat_history_file.parent.mkdir(parents=True, exist_ok=True)
         else:
             self.chat_history_file = None