updated for version 7.2-180
diff --git a/src/macros.h b/src/macros.h
index afe3572..68ea6bc 100644
--- a/src/macros.h
+++ b/src/macros.h
@@ -284,7 +284,7 @@
# define mb_cptr2len(p) (enc_utf8 ? utf_ptr2len(p) : (*mb_ptr2len)(p))
# define MB_COPY_CHAR(f, t) if (has_mbyte) mb_copy_char(&f, &t); else *t++ = *f++
-# define MB_CHARLEN(p) (has_mbyte ? mb_charlen(p) : STRLEN(p))
+# define MB_CHARLEN(p) (has_mbyte ? mb_charlen(p) : (int)STRLEN(p))
# define PTR2CHAR(p) (has_mbyte ? mb_ptr2char(p) : (int)*(p))
#else
# define mb_ptr_adv(p) ++p