diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 2332d2e60..cfbd9576e 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -136,7 +136,11 @@ class Coder:
 
         self.main_model = main_model
 
-        self.io.tool_output(f"Model: {main_model.name} using {self.edit_format} edit format")
+        weak_model = main_model.weak_model
+        self.io.tool_output(
+            f"Models: {main_model.name} with {self.edit_format} edit format, weak model"
+            f" {weak_model.name}"
+        )
 
         self.show_diffs = show_diffs
 
@@ -212,7 +216,7 @@ class Coder:
             self.io.tool_output(f"Added {fname} to the chat.")
 
         self.summarizer = ChatSummary(
-            self.main_model.get_weak_model(),
+            self.main_model.weak_model,
             self.main_model.max_chat_history_tokens,
         )
 
diff --git a/aider/history.py b/aider/history.py
index 9ed866554..3acd368b5 100644
--- a/aider/history.py
+++ b/aider/history.py
@@ -124,7 +124,7 @@ def main():
 
         assistant.append(line)
 
-    summarizer = ChatSummary(models.Model.get_weak_model())
+    summarizer = ChatSummary(models.Model(models.DEFAULT_WEAK_MODEL_NAME))
     summary = summarizer.summarize(messages[-40:])
     dump(summary)
 
diff --git a/aider/main.py b/aider/main.py
index 61c76a8d6..dedff7791 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -196,7 +196,7 @@ def main(argv=None, input=None, output=None, force_git_root=None):
         const=default_4_turbo_model,
         help=f"Use {default_4_turbo_model} model for the main chat",
     )
-    default_3_model_name = "gpt-3.5-turbo-0125"
+    default_3_model_name = "gpt-3.5-turbo"
     core_group.add_argument(
         "--35turbo",
         "--35-turbo",
@@ -252,6 +252,15 @@ def main(argv=None, input=None, output=None, force_git_root=None):
         default=None,
         help="Specify what edit format GPT should use (default depends on model)",
     )
+    core_group.add_argument(
+        "--weak-model",
+        metavar="WEAK_MODEL",
+        default=None,
+        help=(
+            "Specify the model to use for commit messages and chat history summarization (default"
+            " depends on --model)"
+        ),
+    )
     model_group.add_argument(
         "--map-tokens",
         type=int,
@@ -583,10 +592,9 @@ def main(argv=None, input=None, output=None, force_git_root=None):
 
     # Check in advance that we have model metadata
     try:
-        main_model = models.Model(args.model)
+        main_model = models.Model(args.model, weak_model=args.weak_model)
     except models.NoModelInfo as err:
-        io.tool_error(f"Unknown model {args.model}.")
-        io.tool_error(str(err))
+        io.tool_error(f"Unknown model {err}.")
         return 1
 
     try:
diff --git a/aider/models.py b/aider/models.py
index bd48d486b..bf79ba7e3 100644
--- a/aider/models.py
+++ b/aider/models.py
@@ -1,7 +1,6 @@
 import json
 import math
 from dataclasses import dataclass, fields
-from typing import Optional
 
 import litellm
 from PIL import Image
@@ -9,6 +8,7 @@ from PIL import Image
 from aider.dump import dump  # noqa: F401
 
 DEFAULT_MODEL_NAME = "gpt-4-1106-preview"
+DEFAULT_WEAK_MODEL_NAME = "gpt-3.5-turbo"
 
 
 class NoModelInfo(Exception):
@@ -16,15 +16,15 @@ class NoModelInfo(Exception):
     Exception raised when model information cannot be retrieved.
     """
 
-    def __init__(self, message: Optional[str] = None):
-        super().__init__(message or "No model information available.")
+    def __init__(self, model):
+        super().__init__(model)
 
 
 @dataclass
 class ModelSettings:
     name: str
     edit_format: str
-    weak_model_name: str = "gpt-3.5-turbo-0125"
+    weak_model_name: str = DEFAULT_WEAK_MODEL_NAME
     use_repo_map: bool = False
     send_undo_reply: bool = False
     accepts_images: bool = False
@@ -112,23 +112,22 @@ MODEL_SETTINGS = [
 class Model:
     name = None
 
-    weak_model_name = "gpt-3.5-turbo-0125"
-
     edit_format = "whole"
     use_repo_map = False
     send_undo_reply = False
     accepts_images = False
+    weak_model_name = DEFAULT_WEAK_MODEL_NAME
 
     max_chat_history_tokens = 1024
     weak_model = None
 
-    def __init__(self, model):
+    def __init__(self, model, weak_model=None):
         self.name = model
 
         try:
             self.info = litellm.get_model_info(model)
-        except Exception as err:
-            raise NoModelInfo(str(err))
+        except Exception:
+            raise NoModelInfo(model)
 
         if self.info.get("max_input_tokens", 0) < 32 * 1024:
             self.max_chat_history_tokens = 1024
@@ -136,6 +135,7 @@ class Model:
             self.max_chat_history_tokens = 2 * 1024
 
         self.configure_model_settings(model)
+        self.get_weak_model(weak_model)
 
     def configure_model_settings(self, model):
         for ms in MODEL_SETTINGS:
@@ -159,13 +159,25 @@ class Model:
     def __str__(self):
         return self.name
 
-    def get_weak_model(self):
-        if not self.weak_model:
-            self.weak_model = Model(self.weak_model_name)
+    def get_weak_model(self, provided_weak_model_name):
+        # If weak_model_name is provided, override the model settings
+        if provided_weak_model_name:
+            self.weak_model_name = provided_weak_model_name
+
+        if self.weak_model_name == self.name:
+            self.weak_model = self
+            return
+
+        try:
+            self.info = litellm.get_model_info(self.weak_model_name)
+        except Exception:
+            raise NoModelInfo(self.weak_model_name)
+
+        self.weak_model = Model(self.weak_model_name)
         return self.weak_model
 
     def commit_message_models(self):
-        return [self.get_weak_model()]
+        return [self.weak_model]
 
     def tokenizer(self, text):
         return litellm.encode(model=self.name, text=text)