diff --git a/kernel/timeout.c b/kernel/timeout.c
index b8c37bb7e94..0dd93d5d026 100644
--- a/kernel/timeout.c
+++ b/kernel/timeout.c
@@ -18,6 +18,17 @@ static sys_dlist_t timeout_list = SYS_DLIST_STATIC_INIT(&timeout_list);
 
 static struct k_spinlock timeout_lock;
 
+/* On multiprocessor setups, it's possible to have multiple
+ * sys_clock_announce() calls arrive in parallel (the latest to exit
+ * the driver will generally be announcing zero ticks).  But we want
+ * the list of timeouts to be executed serially, so as not to confuse
+ * application code.  This lock wraps the announce loop, external to
+ * the nested timeout_lock.
+ */
+#ifdef CONFIG_SMP
+static struct k_spinlock ann_lock;
+#endif
+
 #define MAX_WAIT (IS_ENABLED(CONFIG_SYSTEM_CLOCK_SLOPPY_IDLE) \
 		  ? K_TICKS_FOREVER : INT_MAX)
 
@@ -242,6 +253,10 @@ void sys_clock_announce(int32_t ticks)
 	z_time_slice(ticks);
 #endif
 
+#ifdef CONFIG_SMP
+	k_spinlock_key_t ann_key = k_spin_lock(&ann_lock);
+#endif
+
 	k_spinlock_key_t key = k_spin_lock(&timeout_lock);
 
 	announce_remaining = ticks;
@@ -270,6 +285,10 @@ void sys_clock_announce(int32_t ticks)
 	sys_clock_set_timeout(next_timeout(), false);
 
 	k_spin_unlock(&timeout_lock, key);
+
+#ifdef CONFIG_SMP
+	k_spin_unlock(&ann_lock, ann_key);
+#endif
 }
 
 int64_t sys_clock_tick_get(void)