Index: src/third-party/rapidyaml/ryml_all.hpp
--- src/third-party/rapidyaml/ryml_all.hpp.orig
+++ src/third-party/rapidyaml/ryml_all.hpp
@@ -503,6 +503,11 @@ C4_FOR_EACH(PRN_STRUCT_OFFSETS, a, b, c);
     #define C4_WORDSIZE 8
     #define C4_BYTE_ORDER _C4EL
 
+#elif defined(__sparc64__)
+
+    #define C4_WORDSIZE 8
+    #define C4_BYTE_ORDER _C4EB
+
 #elif defined(__EMSCRIPTEN__)
 #   define C4_BYTE_ORDER _C4EL
 #   define C4_WORDSIZE 4
