diff --git a/aider/main.py b/aider/main.py
index dd0d87734..817c212da 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -189,6 +189,10 @@ def main(args=None, input=None, output=None):
 
     io.tool(*sys.argv, log_only=True)
 
+    if not args.openai_api_key:
+        io.tool_error("No OpenAI API key provided. Use --openai-api-key or env OPENAI_API_KEY,")
+        return 1
+
     coder = Coder(
         io,
         main_model=args.model,
@@ -202,6 +206,7 @@ def main(args=None, input=None, output=None):
         verbose=args.verbose,
         openai_api_key=args.openai_api_key,
     )
+
     if args.dirty_commits:
         coder.commit(ask=True, prefix="wip: ", which="repo_files")