diff -rupN pjproject-2.6/pjlib/include/pj/config.h pjproject-2.6-new/pjlib/include/pj/config.h
--- pjproject-2.6/pjlib/include/pj/config.h	2017-09-01 18:51:57.003898294 +0200
+++ pjproject-2.6-new/pjlib/include/pj/config.h	2017-09-01 18:52:01.907894418 +0200
@@ -341,7 +341,19 @@
 #   define PJ_HAS_PENTIUM	0
 #   define PJ_IS_LITTLE_ENDIAN	1
 #   define PJ_IS_BIG_ENDIAN	0
-		
+
+#elif defined (PJ_M_S390) || defined(__s390) || defined(__s390__) || \
+      defined(__S390__) || defined(_M_S390)
+    /*
+     * S390, big endian
+     */
+#   undef PJ_M_S390
+#   define PJ_M_S390		1
+#   define PJ_M_NAME		"s390"
+#   define PJ_HAS_PENTIUM	0
+#   define PJ_IS_LITTLE_ENDIAN	0
+#   define PJ_IS_BIG_ENDIAN	1
+
 #else
 #   error "Please specify target machine."
 #endif
diff -rupN pjproject-2.6/third_party/webrtc/src/webrtc/typedefs.h pjproject-2.6-new/third_party/webrtc/src/webrtc/typedefs.h
--- pjproject-2.6/third_party/webrtc/src/webrtc/typedefs.h	2017-09-01 18:51:57.003898294 +0200
+++ pjproject-2.6-new/third_party/webrtc/src/webrtc/typedefs.h	2017-09-01 18:52:01.908894418 +0200
@@ -58,6 +58,9 @@
 # elif (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
 #  define WEBRTC_ARCH_BIG_ENDIAN
 # endif
+#elif defined(__s390__)
+# define WEBRTC_ARCH_32_BITS
+# define WEBRTC_ARCH_BIG_ENDIAN
 #else
 #error Please add support for your architecture in typedefs.h
 #endif