diff --git a/codex-rs/core/src/agent/control.rs b/codex-rs/core/src/agent/control.rs
index 17423a910f..4b7bf32b80 100644
--- a/codex-rs/core/src/agent/control.rs
+++ b/codex-rs/core/src/agent/control.rs
@@ -686,6 +686,7 @@ impl AgentControl {
             )
             .await;
         if result.is_ok() {
+            self.watchdogs.note_owner_input(agent_id).await;
             self.state
                 .update_last_task_message(agent_id, last_task_message);
         }
@@ -1264,6 +1265,16 @@ impl AgentControl {
         self.watchdogs.force_due_for_tests(target_thread_id).await;
     }
 
+    #[cfg(test)]
+    pub(crate) async fn watchdog_owner_idle_since_is_none_for_tests(
+        &self,
+        target_thread_id: ThreadId,
+    ) -> Option<bool> {
+        self.watchdogs
+            .owner_idle_since_is_none_for_tests(target_thread_id)
+            .await
+    }
+
     #[cfg(test)]
     pub(crate) async fn set_watchdog_active_helper_for_tests(
         &self,
diff --git a/codex-rs/core/src/agent/control_tests.rs b/codex-rs/core/src/agent/control_tests.rs
index a34f2c82c3..732838cd0d 100644
--- a/codex-rs/core/src/agent/control_tests.rs
+++ b/codex-rs/core/src/agent/control_tests.rs
@@ -417,6 +417,48 @@ async fn send_input_submits_user_message() {
     assert_eq!(captured, Some(expected));
 }
 
+#[tokio::test]
+async fn send_input_resets_watchdog_owner_idle_state() {
+    let harness = AgentControlHarness::new().await;
+    let (owner_thread_id, _thread) = harness.start_thread().await;
+    let target_thread_id = ThreadId::new();
+
+    harness
+        .control
+        .register_watchdog(WatchdogRegistration {
+            owner_thread_id,
+            target_thread_id,
+            child_depth: 0,
+            interval_s: 30,
+            prompt: String::new(),
+            config: harness.config.clone(),
+        })
+        .await
+        .expect("watchdog registration should succeed");
+
+    assert_eq!(
+        harness
+            .control
+            .watchdog_owner_idle_since_is_none_for_tests(target_thread_id)
+            .await,
+        Some(false)
+    );
+
+    harness
+        .control
+        .send_input(owner_thread_id, text_input("ping"))
+        .await
+        .expect("send_input should succeed");
+
+    assert_eq!(
+        harness
+            .control
+            .watchdog_owner_idle_since_is_none_for_tests(target_thread_id)
+            .await,
+        Some(true)
+    );
+}
+
 #[test]
 fn build_agent_inbox_items_emits_function_call_and_output() {
     let sender_thread_id = ThreadId::new();
diff --git a/codex-rs/core/src/agent/watchdog.rs b/codex-rs/core/src/agent/watchdog.rs
index 86b068ed7f..71d4246a83 100644
--- a/codex-rs/core/src/agent/watchdog.rs
+++ b/codex-rs/core/src/agent/watchdog.rs
@@ -448,6 +448,16 @@ impl WatchdogManager {
         true
     }
 
+    pub(crate) async fn note_owner_input(&self, owner_thread_id: ThreadId) {
+        let mut registrations = self.registrations.lock().await;
+        for entry in registrations.values_mut() {
+            if entry.registration.owner_thread_id == owner_thread_id {
+                entry.owner_idle_since = None;
+                entry.owner_was_running = true;
+            }
+        }
+    }
+
     #[cfg(test)]
     pub(crate) async fn force_due_for_tests(&self, target_thread_id: ThreadId) {
         let mut registrations = self.registrations.lock().await;
@@ -456,6 +466,17 @@ impl WatchdogManager {
         }
     }
 
+    #[cfg(test)]
+    pub(crate) async fn owner_idle_since_is_none_for_tests(
+        &self,
+        target_thread_id: ThreadId,
+    ) -> Option<bool> {
+        let registrations = self.registrations.lock().await;
+        registrations
+            .get(&target_thread_id)
+            .map(|entry| entry.owner_idle_since.is_none())
+    }
+
     async fn update_after_spawn(
         &self,
         target_thread_id: ThreadId,
diff --git a/codex-rs/core/src/config/mod.rs b/codex-rs/core/src/config/mod.rs
index a55d9b3a6f..92c4bfb06f 100644
--- a/codex-rs/core/src/config/mod.rs
+++ b/codex-rs/core/src/config/mod.rs
@@ -145,7 +145,7 @@ pub(crate) const PROJECT_DOC_MAX_BYTES: usize = 32 * 1024; // 32 KiB
 pub(crate) const DEFAULT_AGENT_MAX_THREADS: Option<usize> = Some(6);
 pub(crate) const DEFAULT_AGENT_MAX_DEPTH: i32 = 1;
 pub(crate) const DEFAULT_AGENT_JOB_MAX_RUNTIME_SECONDS: Option<u64> = None;
-pub(crate) const DEFAULT_WATCHDOG_INTERVAL_S: i64 = 60;
+pub(crate) const DEFAULT_WATCHDOG_INTERVAL_S: i64 = 10;
 
 pub const CONFIG_TOML_FILE: &str = "config.toml";
 const OPENAI_BASE_URL_ENV_VAR: &str = "OPENAI_BASE_URL";