diff --git a/headers/os/mail/mail_encoding.h b/headers/os/mail/mail_encoding.h
index 90765ff227..eac45759f5 100644
--- a/headers/os/mail/mail_encoding.h
+++ b/headers/os/mail/mail_encoding.h
@@ -10,9 +10,9 @@
 #include <sys/types.h>
 
 
-#define B_MAIL_UTF8_CONVERSION ((uint32) -1)
+#define B_MAIL_NULL_CONVERSION ((uint32) -1)
+#define B_MAIL_UTF8_CONVERSION ((uint32) -2)
 // For specifying the UTF-8 character set when converting to/from UTF-8.
-#define B_MAIL_NULL_CONVERSION ((uint32) -2)
 #define B_MAIL_US_ASCII_CONVERSION ((uint32) -3)
 // Plain 7 bit ASCII character set.  A subset of UTF-8, but some mail software
 // specifies it so we need to recognize it.