diff --git a/hw/a9mpcore.c b/hw/a9mpcore.c
index c2ff74d4b6cab5df56c2bced61cc71b3a6a450a2..ebd5b2917342056f622d3fe60d743268fe9b63ea 100644
--- a/hw/a9mpcore.c
+++ b/hw/a9mpcore.c
@@ -75,7 +75,7 @@ static void a9_scu_write(void *opaque, target_phys_addr_t offset,
         break;
     default:
         fprintf(stderr, "Invalid size %u in write to a9 scu register %x\n",
-                size, offset);
+                size, (unsigned)offset);
         return;
     }