diff --git a/lib/freebl/verified/kremlin/include/kremlin/internal/types.h b/lib/freebl/verified/kremlin/include/kremlin/internal/types.h
index 40fac22..3896387 100644
--- a/lib/freebl/verified/kremlin/include/kremlin/internal/types.h
+++ b/lib/freebl/verified/kremlin/include/kremlin/internal/types.h
@@ -58,7 +58,7 @@ typedef __m128i FStar_UInt128_uint128;
 #elif !defined(KRML_VERIFIED_UINT128) && !defined(_MSC_VER) && \
     (defined(__x86_64__) || defined(__x86_64) || defined(__aarch64__) || \
     (defined(__powerpc64__) && defined(__LITTLE_ENDIAN__)) || \
-     defined(__s390x__))
+     defined(__s390x__) || (defined(__riscv) && __riscv_xlen == 64))
 typedef unsigned __int128 FStar_UInt128_uint128;
 #else
 typedef struct FStar_UInt128_uint128_s {
diff --git a/lib/freebl/verified/kremlin/kremlib/dist/minimal/fstar_uint128_gcc64.h b/lib/freebl/verified/kremlin/kremlib/dist/minimal/fstar_uint128_gcc64.h
index 1ecedc7..e187e61 100644
--- a/lib/freebl/verified/kremlin/kremlib/dist/minimal/fstar_uint128_gcc64.h
+++ b/lib/freebl/verified/kremlin/kremlib/dist/minimal/fstar_uint128_gcc64.h
@@ -27,7 +27,7 @@
 #if !defined(KRML_VERIFIED_UINT128) && !defined(_MSC_VER) && \
     (defined(__x86_64__) || defined(__x86_64) || defined(__aarch64__) || \
     (defined(__powerpc64__) && defined(__LITTLE_ENDIAN__)) || \
-     defined(__s390x__))
+     defined(__s390x__) || (defined(__riscv) && __riscv_xlen == 64))
 
 /* GCC + using native unsigned __int128 support */