diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index e7d26af..14b0a70f 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -531,6 +531,16 @@
 	kmem_cache_free(posix_timers_cache, tmr);
 }
 
+static struct k_clock *clockid_to_kclock(const clockid_t id)
+{
+	if (id < 0)
+		return &clock_posix_cpu;
+
+	if (id >= MAX_CLOCKS || !posix_clocks[id].clock_getres)
+		return NULL;
+	return &posix_clocks[id];
+}
+
 /* Create a POSIX.1b interval timer. */
 
 SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,