diff --git a/extras/collect/collect.c b/extras/collect/collect.c
index 9fb6737d9b4..ce49b9f410c 100644
--- a/extras/collect/collect.c
+++ b/extras/collect/collect.c
@@ -147,7 +147,7 @@ static int checkout(int fd)
 			if (!ptr && word < (buf + len)) {
 				bufsize = bufsize << 1;
 				if (debug)
-					fprintf(stderr, "ID overflow, restarting with size %d\n", bufsize);
+					fprintf(stderr, "ID overflow, restarting with size %zi\n", bufsize);
 				free(buf);
 				lseek(fd, 0, SEEK_SET);
 				goto restart;