diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index ce32cf741b250939de562ab05bd598fb30f10986..76801b9b481eb6d4c19155204cfcdd4123c7611f 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -685,6 +685,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	 * set up the signal and overrun bookkeeping.
 	 */
 	timer->it.cpu.incr = timespec64_to_ns(&new->it_interval);
+	timer->it_interval = ns_to_ktime(timer->it.cpu.incr);
 
 	/*
 	 * This acts as a modification timestamp for the timer,