diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 9edf78b02..f97edf47d 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -34,7 +34,13 @@ class Coder:
 
     @classmethod
     def create(
-        self, main_model, io, openai_api_key, openai_api_base="https://api.openai.com/v1", **kwargs
+        self,
+        main_model,
+        edit_format,
+        io,
+        openai_api_key,
+        openai_api_base="https://api.openai.com/v1",
+        **kwargs,
     ):
         from . import EditBlockCoder, WholeFileCoder
 
@@ -50,9 +56,12 @@ class Coder:
                     )
                 main_model = models.GPT35_16k
 
-        if main_model.edit_format == "diff":
+        if edit_format is None:
+            edit_format = main_model.edit_format
+
+        if edit_format == "diff":
             return EditBlockCoder(main_model, io, **kwargs)
-        elif main_model.edit_format == "whole":
+        elif edit_format == "whole":
             return WholeFileCoder(main_model, io, **kwargs)
         else:
             raise ValueError(f"{main_model} has unknown edit format {main_model.edit_format}")
diff --git a/aider/main.py b/aider/main.py
index 161406858..a7b6c91d2 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -93,6 +93,12 @@ def main(args=None, input=None, output=None):
         const=models.GPT35_16k.name,
         help=f"Use {models.GPT35_16k.name} model for the main chat (gpt-4 is better)",
     )
+    parser.add_argument(
+        "--edit-format",
+        metavar="EDIT_FORMAT",
+        default=None,
+        help="Specify what edit format GPT should use (default depends on model)",
+    )
     parser.add_argument(
         "--pretty",
         action="store_true",
@@ -231,6 +237,7 @@ def main(args=None, input=None, output=None):
 
     coder = Coder.create(
         main_model,
+        args.edit_format,
         io,
         args.openai_api_key,
         args.openai_api_base,