diff --git a/aider/coder.py b/aider/coder.py
index b105c4715..99ae29e28 100755
--- a/aider/coder.py
+++ b/aider/coder.py
@@ -50,11 +50,12 @@ class Coder:
         map_tokens=1024,
         verbose=False,
         openai_api_key=None,
+        openai_api_base=None,
     ):
         if not openai_api_key:
             raise MissingAPIKeyError("No OpenAI API key provided.")
         openai.api_key = openai_api_key
-        openai.api_base = args.openai_api_base
+        openai.api_base = openai_api_base
 
         self.verbose = verbose
         self.abs_fnames = set()
diff --git a/aider/main.py b/aider/main.py
index 14ea79bb1..505e0f908 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -227,6 +227,7 @@ def main(args=None, input=None, output=None):
         map_tokens=args.map_tokens,
         verbose=args.verbose,
         openai_api_key=args.openai_api_key,
+        openai_api_base=args.openai_api_base,
     )
 
     if args.dirty_commits: