diff -Naur gzip-1.5-orig/gzip.h gzip-1.5/gzip.h
--- gzip-1.5-orig/gzip.h	2012-01-01 18:53:58.000000000 +1000
+++ gzip-1.5/gzip.h	2013-02-05 22:08:44.498810902 +1000
@@ -42,6 +42,7 @@
 #include <sys/types.h> /* for off_t */
 #include <time.h>
 #include <string.h>
+#include <stdbool.h>
 #define memzero(s, n) memset ((voidp)(s), 0, (n))
 
 #ifndef RETSIGTYPE
@@ -323,4 +324,4 @@
 extern int inflate (void);
 
         /* in yesno.c */
-extern int yesno (void);
+extern bool yesno (void);