diff --git a/hw/dma/rc4030.c b/hw/dma/rc4030.c
index 17c8518feafb0c3e281ac691e05a5223fc72a095..41fc0434642bb828738fff4e48b8ba02a4903145 100644
--- a/hw/dma/rc4030.c
+++ b/hw/dma/rc4030.c
@@ -460,7 +460,7 @@ static void rc4030_write(void *opaque, hwaddr addr, uint64_t data,
         break;
     /* Interval timer reload */
     case 0x0228:
-        s->itr = val;
+        s->itr = val & 0x01FF;
         qemu_irq_lower(s->timer_irq);
         set_next_tick(s);
         break;