diff --git a/regenc.c b/regenc.c
index fc131d2533..eb523e1ae5 100644
--- a/regenc.c
+++ b/regenc.c
@@ -57,7 +57,7 @@ onigenc_mbclen(const OnigUChar* p,const OnigUChar* e, OnigEncoding enc)
   int ret = ONIGENC_PRECISE_MBC_ENC_LEN(enc, p, e);
   if (ONIGENC_MBCLEN_CHARFOUND_P(ret)) {
     ret = ONIGENC_MBCLEN_CHARFOUND_LEN(ret);
-    if (ret > (int)(e - p)) ret = (int)(e - p); // just for case
+    if (p + ret > e) ret = (int)(e - p); // just for case
     return ret;
   }
   else if (ONIGENC_MBCLEN_NEEDMORE_P(ret)) {
diff --git a/regexec.c b/regexec.c
index 81d0ea6a6b..9e6f503ed0 100644
--- a/regexec.c
+++ b/regexec.c
@@ -3521,7 +3521,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
 	n = pend - pstart;
 	DATA_ENSURE(n);
 	sprev = s;
-	STRING_CMP_IC(case_fold_flag, pstart, &s, (int)n, end);
+	STRING_CMP_IC(case_fold_flag, pstart, &s, n, end);
 	while (sprev + (len = enclen(encode, sprev, end)) < s)
 	  sprev += len;