diff --git a/libisofs/make_isohybrid_mbr.c b/libisofs/make_isohybrid_mbr.c
index 9caa347..ba094b5 100644
--- a/libisofs/make_isohybrid_mbr.c
+++ b/libisofs/make_isohybrid_mbr.c
@@ -26,6 +26,7 @@
 #include "filesrc.h"
 #include "ecma119.h"
 #include "eltorito.h"
+#include "system_area.h"
 
 
 /* This code stems from syslinux-3.72/utils/isohybrid, a perl script
diff --git a/libisofs/system_area.c b/libisofs/system_area.c
index b4d71c7..43e82ff 100644
--- a/libisofs/system_area.c
+++ b/libisofs/system_area.c
@@ -1251,8 +1251,8 @@ void iso_random_uuid(Ecma119Image *t, uint8_t uuid[16])
 
 #else
 
-    salt = iso_crc32_gpt((unsigned char *) t, sizeof(Ecma119Image), 0); 
-    salt ^= getpid();
+    pid = getpid();
+    salt = iso_crc32_gpt((unsigned char *) t, sizeof(Ecma119Image), 0) ^ pid; 
 
     /* This relies on the uniqueness of the template and the rareness of
        bootable ISO image production via libisofs. Estimated 53 bits of