diff --git a/src/to_pro.c b/src/to_pro.c
index d52645c..88ff8f1 100755
--- a/src/to_pro.c
+++ b/src/to_pro.c
@@ -43,7 +43,7 @@ int g_crlf = 0;
 
 void make_legal_prodos_name(char *new_name, char *old_name);
 
-static int hex(uint8_t c)
+static int hex(byte c)
 {
 	if (c >= '0' && c <= '9') return c - '0';
 	if (c >= 'a' && c <= 'f') return c + 10 - 'a';