diff --git a/codex-rs/mcp-server/src/main.rs b/codex-rs/mcp-server/src/main.rs
index 4e546ffe53..87e8d7bbe2 100644
--- a/codex-rs/mcp-server/src/main.rs
+++ b/codex-rs/mcp-server/src/main.rs
@@ -1,4 +1,5 @@
 //! Prototype MCP server.
+#![deny(clippy::print_stdout, clippy::print_stderr)]
 
 use std::io::Result as IoResult;