diff --git a/src/device/oprom/realmode/x86.c b/src/device/oprom/realmode/x86.c
index 461cb06..919fd6d 100644
--- a/src/device/oprom/realmode/x86.c
+++ b/src/device/oprom/realmode/x86.c
@@ -80,7 +80,7 @@
 	memcpy((void *)0xfffd9, &ident, 7);
 
 	/* system model: IBM-AT */
-	write8(0xffffe, 0xfc);
+	write8((void *)0xffffe, 0xfc);
 }
 
 static int (*intXX_handler[256])(void) = { NULL };