diff --git a/include/boost/charconv/detail/integer_search_trees.hpp b/include/boost/charconv/detail/integer_search_trees.hpp
index 9b4de091..52e8ec12 100644
--- a/include/boost/charconv/detail/integer_search_trees.hpp
+++ b/include/boost/charconv/detail/integer_search_trees.hpp
@@ -24,7 +24,7 @@ BOOST_CHARCONV_CXX14_CONSTEXPR int num_digits(T x) noexcept
 
     while (x)
     {
-        x /= 10;
+        x /= static_cast<T>(10);
         ++digits;
     }
 
diff --git a/include/boost/charconv/detail/to_chars_integer_impl.hpp b/include/boost/charconv/detail/to_chars_integer_impl.hpp
index 9f2ee390..fe42c456 100644
--- a/include/boost/charconv/detail/to_chars_integer_impl.hpp
+++ b/include/boost/charconv/detail/to_chars_integer_impl.hpp
@@ -238,7 +238,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_128integer_impl(char* first, c
                         #endif
                         )
     {
-        if (value < 0)
+        if (value < static_cast<Integer>(0))
         {
             is_negative = true;
             unsigned_value = -(static_cast<Unsigned_Integer>(value));
@@ -278,7 +278,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_128integer_impl(char* first, c
     int num_chars[5] {};
     int i = 0;
 
-    while (converted_value != 0)
+    while (converted_value != static_cast<Unsigned_Integer>(0))
     {
         auto digits = static_cast<std::uint32_t>(converted_value % ten_9);
         num_chars[i] = num_digits(digits);
@@ -320,7 +320,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_integer_impl(char* first, char
         return {last, std::errc::invalid_argument};
     }
 
-    if (value == 0)
+    if (value == static_cast<Integer>(0))
     {
         *first++ = '0';
         return {first, std::errc()};
@@ -331,7 +331,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_integer_impl(char* first, char
 
     BOOST_IF_CONSTEXPR (std::is_signed<Integer>::value)
     {
-        if (value < 0)
+        if (value < static_cast<Integer>(0))
         {
             *first++ = '-';
             unsigned_value = static_cast<Unsigned_Integer>(detail::apply_sign(value));
@@ -358,7 +358,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_integer_impl(char* first, char
     switch (base)
     {
         case 2:
-            while (unsigned_value != 0)
+            while (unsigned_value != static_cast<Unsigned_Integer>(0))
             {
                 *end-- = static_cast<char>(zero + (unsigned_value & 1U)); // 1<<1 - 1
                 unsigned_value >>= static_cast<Unsigned_Integer>(1);
@@ -366,7 +366,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_integer_impl(char* first, char
             break;
 
         case 4:
-            while (unsigned_value != 0)
+            while (unsigned_value != static_cast<Unsigned_Integer>(0))
             {
                 *end-- = static_cast<char>(zero + (unsigned_value & 3U)); // 1<<2 - 1
                 unsigned_value >>= static_cast<Unsigned_Integer>(2);
@@ -374,7 +374,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_integer_impl(char* first, char
             break;
 
         case 8:
-            while (unsigned_value != 0)
+            while (unsigned_value != static_cast<Unsigned_Integer>(0))
             {
                 *end-- = static_cast<char>(zero + (unsigned_value & 7U)); // 1<<3 - 1
                 unsigned_value >>= static_cast<Unsigned_Integer>(3);
@@ -382,7 +382,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_integer_impl(char* first, char
             break;
 
         case 16:
-            while (unsigned_value != 0)
+            while (unsigned_value != static_cast<Unsigned_Integer>(0))
             {
                 *end-- = digit_table[static_cast<std::size_t>(unsigned_value & 15U)]; // 1<<4 - 1
                 unsigned_value >>= static_cast<Unsigned_Integer>(4);
@@ -390,7 +390,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_integer_impl(char* first, char
             break;
 
         case 32:
-            while (unsigned_value != 0)
+            while (unsigned_value != static_cast<Unsigned_Integer>(0))
             {
                 *end-- = digit_table[static_cast<std::size_t>(unsigned_value & 31U)]; // 1<<5 - 1
                 unsigned_value >>= static_cast<Unsigned_Integer>(5);
@@ -398,7 +398,7 @@ BOOST_CHARCONV_CONSTEXPR to_chars_result to_chars_integer_impl(char* first, char
             break;
 
         default:
-            while (unsigned_value != 0)
+            while (unsigned_value != static_cast<Unsigned_Integer>(0))
             {
                 *end-- = digit_table[static_cast<std::size_t>(unsigned_value % unsigned_base)];
                 unsigned_value /= unsigned_base;