diff --git a/aider/coder.py b/aider/coder.py
index 40b9cd90b..bb2d10ee6 100755
--- a/aider/coder.py
+++ b/aider/coder.py
@@ -113,7 +113,7 @@ class Coder:
             self.io.tool_output("Git repo: none")
             self.find_common_root()
 
-        if main_model.is_gpt4():
+        if main_model.use_repo_map:
             rm_io = io if self.verbose else None
             self.repo_map = RepoMap(
                 map_tokens,
@@ -328,7 +328,7 @@ class Coder:
         ]
 
         main_sys = self.gpt_prompts.main_system
-        if self.main_model.is_gpt4():
+        if self.main_model.use_repo_map:
             main_sys += "\n" + self.gpt_prompts.system_reminder
 
         messages = [
diff --git a/aider/commands.py b/aider/commands.py
index 79be3325e..6598d5d86 100644
--- a/aider/commands.py
+++ b/aider/commands.py
@@ -183,7 +183,7 @@ class Commands:
             "was reset and removed from git.\n"
         )
 
-        if self.coder.main_model.is_gpt4():
+        if self.coder.main_model.send_undo_reply:
             return prompts.undo_command_reply
 
     def cmd_diff(self, args):
diff --git a/aider/models.py b/aider/models.py
index fe5786d59..5703b1e9d 100644
--- a/aider/models.py
+++ b/aider/models.py
@@ -3,6 +3,8 @@ import re
 
 class Model:
     always_available = False
+    use_repo_map = False
+    send_undo_reply = False
 
     def __init__(self, name, tokens=None):
         self.name = name
@@ -17,6 +19,8 @@ class Model:
 
         if self.is_gpt4():
             self.edit_format = "diff"
+            self.use_repo_map = True
+            self.send_undo_reply = True
             return
 
         if self.is_gpt35():