diff --git a/codex-rs/core/src/realtime_conversation.rs b/codex-rs/core/src/realtime_conversation.rs
index 631778d0c1..9533d1d10a 100644
--- a/codex-rs/core/src/realtime_conversation.rs
+++ b/codex-rs/core/src/realtime_conversation.rs
@@ -485,9 +485,7 @@ async fn prepare_realtime_start(
         RealtimeWsMode::Conversational => RealtimeSessionMode::Conversational,
         RealtimeWsMode::Transcription => RealtimeSessionMode::Transcription,
     };
-    let requested_session_id = params
-        .session_id
-        .or_else(|| Some(sess.conversation_id.to_string()));
+    let requested_session_id = params.session_id.or(Some(sess.conversation_id.to_string()));
     let session_config = RealtimeSessionConfig {
         instructions: prompt,
         model,