diff --git a/arch/sandbox/mach-sandbox/include/mach/hostfile.h b/arch/sandbox/mach-sandbox/include/mach/hostfile.h
index 627fe28..54f690b 100644
--- a/arch/sandbox/mach-sandbox/include/mach/hostfile.h
+++ b/arch/sandbox/mach-sandbox/include/mach/hostfile.h
@@ -3,7 +3,7 @@
 
 struct hf_info {
 	int fd;
-	unsigned long base;
+	unsigned long long base;
 	size_t size;
 	const char *devname;
 	const char *filename;