diff --git a/arch/um/kernel/time_kern.c b/arch/um/kernel/time_kern.c
index 86f51d04c98d..87cdbc560d36 100644
--- a/arch/um/kernel/time_kern.c
+++ b/arch/um/kernel/time_kern.c
@@ -87,7 +87,7 @@ void timer_irq(union uml_pt_regs *regs)
 
 void time_init_kern(void)
 {
-	unsigned long long nsecs;
+	long long nsecs;
 
 	nsecs = os_nsecs();
 	set_normalized_timespec(&wall_to_monotonic, -nsecs / BILLION,