diff --git a/common/dynamips_common.h b/common/dynamips_common.h
index 0f72f53..ca3a184 100644
--- a/common/dynamips_common.h
+++ b/common/dynamips_common.h
@@ -71,6 +71,8 @@
 #define ARCH_BYTE_ORDER ARCH_BIG_ENDIAN
 #elif defined(__riscv) || defined(__riscv__)
 #define ARCH_BYTE_ORDER ARCH_LITTLE_ENDIAN
+#elif defined(__s390x__)
+#define ARCH_BYTE_ORDER ARCH_BIG_ENDIAN
 #endif
 
 #ifndef ARCH_BYTE_ORDER