2 files changed, 5 insertions, 4 deletions
diff --git a/include/unicode/iso.h b/include/unicode/iso.h
index 9b20afd..1f5f007 100644
--- a/include/unicode/iso.h
+++ b/include/unicode/iso.h
@@ -2,6 +2,7 @@
 
 #include "types.h"
 
+#include <algorithm>
 #include <stdexcept>
 #include <string>
 #include <unordered_map>
diff --git a/include/unicode/utf.h b/include/unicode/utf.h
index 6d7c2f7..1d2f28e 100644
--- a/include/unicode/utf.h
+++ b/include/unicode/utf.h
@@ -43,8 +43,8 @@ namespace unicode::detail {
  template<typename T, typename std::enable_if_t<is_utf_8_v<T>, bool> = true>
  inline bool validate_utf(const std::basic_string<T>& s)
  {
-  int i{};
-  auto size{s.size()};
+  size_t i{};
+  size_t size{s.size()};
   while (i < size) {
    if (is_utf8_sequence(s[i])) {
     i++;
@@ -86,8 +86,8 @@ namespace unicode::detail {
  template<typename T, typename std::enable_if_t<is_utf_16_v<T>, bool> = true>
  inline bool validate_utf(const std::basic_string<T>& s)
  {
-  int i{};
-  auto size{s.size()};
+  size_t i{};
+  size_t size{s.size()};
   while (i < size) {
    if (is_utf16_sequence(s[i])) {
     i++;