diff -up nvidia-texture-tools/src/nvcore/nvcore.h.orig nvidia-texture-tools/src/nvcore/nvcore.h
--- nvidia-texture-tools/src/nvcore/nvcore.h.orig	2017-11-15 05:24:04.826858170 -0500
+++ nvidia-texture-tools/src/nvcore/nvcore.h	2017-11-15 05:24:18.980858712 -0500
@@ -78,6 +78,8 @@
 #	define NV_CPU_MIPS 1
 #elif defined POSH_CPU_MIPS64
 #	define NV_CPU_MIPS64 1
+#elif defined POSH_CPU_S390
+#	define NV_CPU_S390 1
 #else
 #	error "Unsupported CPU"
 #endif
diff -up nvidia-texture-tools/src/nvcore/poshlib/posh.h.orig nvidia-texture-tools/src/nvcore/poshlib/posh.h
--- nvidia-texture-tools/src/nvcore/poshlib/posh.h.orig	2017-11-15 05:22:08.066853699 -0500
+++ nvidia-texture-tools/src/nvcore/poshlib/posh.h	2017-11-15 05:23:05.949855915 -0500
@@ -527,6 +527,11 @@ Metrowerks:
 #  define POSH_CPU_STRING "PA-RISC"
 #endif
 
+#if defined __s390__ || defined __s390x__
+#  define POSH_CPU_S390 1
+#  define POSH_CPU_STRING "S390"
+#endif
+
 #if !defined POSH_CPU_STRING
 #  error POSH cannot determine target CPU
 #  define POSH_CPU_STRING "Unknown" /* this is here for Doxygen's benefit */