diff --git a/HEX.CPP b/HEX.CPP
index 1353bb4..1094943 100644
--- a/HEX.CPP
+++ b/HEX.CPP
@@ -37,7 +37,7 @@ std::string Hex( uint32_t const value ) noexcept
 {
    char temp_string[ 65 ];
 
-   std::size_t const number_of_characters = ::sprintf( temp_string, "%04lX", static_cast<unsigned long>(value) );
+   std::size_t const number_of_characters = ::sprintf( temp_string, "%04" PRIX32, static_cast<unsigned long>(value) );
 
    return( std::string(temp_string, number_of_characters) );
 }
diff --git a/NMEA0183.H b/NMEA0183.H
index 22dc8f9..4b9d717 100644
--- a/NMEA0183.H
+++ b/NMEA0183.H
@@ -46,6 +46,7 @@ SOFTWARE.
 #include <charconv>
 #include <math.h>
 #include <time.h>
+#include <inttypes.h>
 
 #define STRING_VIEW(_x)  std::string_view(  _x, std::size(_x) - 1)