diff --git a/common/bbu.c b/common/bbu.c
index 4d71fa4..fc82193 100644
--- a/common/bbu.c
+++ b/common/bbu.c
@@ -187,7 +187,7 @@
 		oflags |= O_CREAT;
 	} else {
 		if (!S_ISREG(s.st_mode) && s.st_size < data->len) {
-			printf("Image (%lld) is too big for device (%d)\n",
+			printf("Image (%lld) is too big for device (%zd)\n",
 					s.st_size, data->len);
 		}
 	}