diff --git a/hw/misc/exynos4210_rng.c b/hw/misc/exynos4210_rng.c
index 0756bd3205..674d8eece5 100644
--- a/hw/misc/exynos4210_rng.c
+++ b/hw/misc/exynos4210_rng.c
@@ -217,6 +217,8 @@ static const MemoryRegionOps exynos4210_rng_ops = {
     .read = exynos4210_rng_read,
     .write = exynos4210_rng_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
 };
 
 static void exynos4210_rng_reset(DeviceState *dev)