diff --git a/codex-rs/config/src/config_toml.rs b/codex-rs/config/src/config_toml.rs
index 4d1f3da2a..f33d49180 100644
--- a/codex-rs/config/src/config_toml.rs
+++ b/codex-rs/config/src/config_toml.rs
@@ -448,9 +448,9 @@ pub enum RealtimeWsMode {
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, Default, PartialEq, Eq, JsonSchema)]
 #[serde(rename_all = "snake_case")]
 pub enum RealtimeTransport {
+    #[default]
     #[serde(rename = "webrtc")]
     WebRtc,
-    #[default]
     Websocket,
 }
 
diff --git a/codex-rs/core/src/config/config_tests.rs b/codex-rs/core/src/config/config_tests.rs
index dab42da75..a205b2041 100644
--- a/codex-rs/core/src/config/config_tests.rs
+++ b/codex-rs/core/src/config/config_tests.rs
@@ -6498,10 +6498,8 @@ voice = "marin"
     assert_eq!(
         config.realtime,
         RealtimeConfig {
-            version: RealtimeWsVersion::V2,
-            session_type: RealtimeWsMode::Conversational,
-            transport: RealtimeTransport::Websocket,
             voice: Some(RealtimeVoice::Marin),
+            ..RealtimeConfig::default()
         }
     );
     Ok(())