--- ferret-0.11.8.4/ext/posh.h.s390x	2018-01-04 17:41:28.554656256 +0900
+++ ferret-0.11.8.4/ext/posh.h	2018-01-04 17:47:46.769599536 +0900
@@ -519,6 +519,11 @@
 #  endif
 #endif
 
+#if defined __s390__
+# define POSH_CPU_S390 1
+# define POSH_CPU_STRING "S/390"
+#endif
+
 #if !defined POSH_CPU_STRING
 #  error POSH cannot determine target CPU
 #  define POSH_CPU_STRING "Unknown" /* this is here for Doxygen's benefit */