diff --git a/libzipfile/centraldir.c b/libzipfile/centraldir.c
index 0e264a343..911e2b98b 100644
--- a/libzipfile/centraldir.c
+++ b/libzipfile/centraldir.c
@@ -192,7 +192,7 @@ read_central_dir(Zipfile *file)
 
     // too small to be a ZIP archive?
     if (bufsize < EOCD_LEN) {
-        fprintf(stderr, "Length is %d -- too small\n", bufsize);
+        fprintf(stderr, "Length is %zd -- too small\n", bufsize);
         goto bail;
     }