diff --git a/src/printer_lyb.c b/src/printer_lyb.c
index f8c4bfd..f0f3769 100644
--- a/src/printer_lyb.c
+++ b/src/printer_lyb.c
@@ -239,9 +239,9 @@
     uint64_t num = 0;
 
     /* write the meta chunk information */
-    num = htole64(sib->written & LYB_SIZE_MAX);
+    num = htole64((uint64_t)sib->written & LYB_SIZE_MAX);
     memcpy(meta_buf, &num, LYB_SIZE_BYTES);
-    num = htole64(sib->inner_chunks & LYB_INCHUNK_MAX);
+    num = htole64((uint64_t)sib->inner_chunks & LYB_INCHUNK_MAX);
     memcpy(meta_buf + LYB_SIZE_BYTES, &num, LYB_INCHUNK_BYTES);
 
     LY_CHECK_RET(ly_write_skipped(out, sib->position, (char *)&meta_buf, LYB_META_BYTES));