diff --git a/codex-cli/src/cli.tsx b/codex-cli/src/cli.tsx
index c54b6f1f..bbfc6237 100644
--- a/codex-cli/src/cli.tsx
+++ b/codex-cli/src/cli.tsx
@@ -79,6 +79,8 @@ const cli = meow(
     --flex-mode               Use "flex-mode" processing mode for the request (only supported
                               with models o3 and o4-mini)
 
+    --reasoning <effort>      Set the reasoning effort level (low, medium, high) (default: high)
+
   Dangerous options
     --dangerously-auto-approve-everything
                                Skip all confirmation prompts and execute commands without