diff --git a/codex-rs/code-mode/src/service.rs b/codex-rs/code-mode/src/service.rs
index 74a62474f4..53daf1037d 100644
--- a/codex-rs/code-mode/src/service.rs
+++ b/codex-rs/code-mode/src/service.rs
@@ -157,10 +157,11 @@ pub trait CodeModeSessionProvider: Send + Sync {
 }
 
 /// Selects how a code-mode session is provisioned for a Codex session.
-#[derive(Clone)]
+#[derive(Clone, Default)]
 pub enum SessionProviderSelection {
-    InProcess,
+    #[default]
     Disabled,
+    InProcess,
     Custom(Arc<dyn CodeModeSessionProvider>),
 }
 
@@ -894,7 +895,6 @@ mod tests {
     use super::PendingRuntimeMode;
     use super::RuntimeCommand;
     use super::RuntimeResponse;
-    use super::SessionProviderSelection;
     use super::WaitOutcome;
     use super::WaitRequest;
     use super::WaitToPendingOutcome;
@@ -968,26 +968,6 @@ mod tests {
         );
     }
 
-    #[tokio::test]
-    async fn provider_selection_can_use_in_process_or_disable() {
-        let delegate = Arc::new(NoopCodeModeSessionDelegate);
-
-        assert!(
-            SessionProviderSelection::InProcess
-                .create_session(delegate.clone())
-                .await
-                .unwrap()
-                .is_some()
-        );
-        assert!(
-            SessionProviderSelection::Disabled
-                .create_session(delegate)
-                .await
-                .unwrap()
-                .is_none()
-        );
-    }
-
     #[tokio::test]
     async fn stored_values_are_shared_between_cells_but_not_sessions() {
         let first_session = CodeModeService::new();
diff --git a/codex-rs/core/src/agent/control.rs b/codex-rs/core/src/agent/control.rs
index 026e1840d3..e9d0a4de9e 100644
--- a/codex-rs/core/src/agent/control.rs
+++ b/codex-rs/core/src/agent/control.rs
@@ -151,7 +151,7 @@ fn is_multi_agent_v2_usage_hint_message(item: &ResponseItem, usage_hint_texts: &
 /// An `AgentControl` instance is intended to be created at most once per root thread/session
 /// tree. That same `AgentControl` is then shared with every sub-agent spawned from that root,
 /// which keeps the registry scoped to that root thread rather than the entire `ThreadManager`.
-#[derive(Clone)]
+#[derive(Clone, Default)]
 pub(crate) struct AgentControl {
     /// ID shared by the whole agent control session. This means every sub-agents from a common
     /// root share the same session ID.
@@ -164,18 +164,6 @@ pub(crate) struct AgentControl {
     code_mode_session_provider_selection: codex_code_mode::SessionProviderSelection,
 }
 
-impl Default for AgentControl {
-    fn default() -> Self {
-        Self {
-            session_id: SessionId::default(),
-            manager: Weak::new(),
-            state: Arc::new(AgentRegistry::default()),
-            code_mode_session_provider_selection:
-                codex_code_mode::SessionProviderSelection::Disabled,
-        }
-    }
-}
-
 impl AgentControl {
     /// Construct a new `AgentControl` that can spawn/message agents via the given manager state.
     pub(crate) fn new(