diff --git a/Framework/Foundation/3rdparty/x9/x9.c b/Framework/Foundation/3rdparty/x9/x9.c
index 2ca4bb80237b3..28684183cc954 100644
--- a/Framework/Foundation/3rdparty/x9/x9.c
+++ b/Framework/Foundation/3rdparty/x9/x9.c
@@ -38,6 +38,7 @@
 #if defined(__x86_64__) || defined(__i386__)
 #include <immintrin.h> /* _mm_pause */
 #elif defined(__aarch64__)
+#elif defined(__riscv)
 #else
 #error Not supported architecture
 #endif
@@ -370,6 +371,8 @@ void x9_read_from_inbox_spin(x9_inbox* const inbox,
     _mm_pause();
 #elif defined(__aarch64__)
     __asm__ __volatile__ ("yield");
+#elif defined(__riscv)
+    __asm__ __volatile__ (".4byte 0x0100000F"); /* PAUSE hint (Zihintpause); NOP if unsupported */
 #else
 #error Not supported architecture
 #endif
diff --git a/Utilities/rANS/include/rANS/internal/common/defines.h b/Utilities/rANS/include/rANS/internal/common/defines.h
index 21afb4ff01750..d053a2e67dab3 100644
--- a/Utilities/rANS/include/rANS/internal/common/defines.h
+++ b/Utilities/rANS/include/rANS/internal/common/defines.h
@@ -40,7 +40,7 @@
 #error RANS_FMA cannot be directly set
 #endif
 
-#if (defined(__x86_64__) || defined(__aarch64__))
+#if (defined(__x86_64__) || defined(__aarch64__) || (defined(__riscv) && __riscv_xlen == 64))
 #define RANS_COMPAT
 #if defined(__SIZEOF_INT128__)
 #define RANS_SINGLE_STREAM