diff --git a/util/lar/stream.c b/util/lar/stream.c
index f5046c19ff..41ef815c87 100644
--- a/util/lar/stream.c
+++ b/util/lar/stream.c
@@ -309,7 +309,7 @@ int lar_add_bootblock(struct lar *lar, const char *bootblock)
 		if (s.st_size != BOOTBLOCK_SIZE) {
 			err("Bootblock %s does not appear to be a bootblock.\n",
 			    bootblock);
-			err("It is the wrong size; it should be %d bytes and it is %d bytes\n", 
+			err("It is the wrong size; it should be %d bytes and it is %ld bytes\n", 
 				BOOTBLOCK_SIZE, s.st_size);
 			close(fd);
 			return -1;