1 files changed, 2 insertions, 1 deletions
diff --git a/lib.c b/lib.c
index beb5762c..2e5091dd 100644
--- a/lib.c
+++ b/lib.c
@@ -3949,7 +3949,8 @@ val int_str(val str, val base)
 
   if ((value == LONG_MAX || value == LONG_MIN) && errno == ERANGE) {
     val bignum = make_bignum();
-    unsigned char *ucs = utf8_dup_to_uc(wcs);
+    size_t size;
+    unsigned char *ucs = utf8_dup_to_buf(wcs, &size, 1);
     mp_err err = mp_read_radix(mp(bignum), ucs, b);
 
     free(ucs); /* TODO: make wchar_t version of mp_read_radix. */