diff --git a/include/openssl/base.h b/include/openssl/base.h
index 90924e629..79c444458 100644
--- a/include/openssl/base.h
+++ b/include/openssl/base.h
@@ -105,6 +105,10 @@ extern "C" {
 #elif defined(__MIPSEL__) && defined(__LP64__)
 #define OPENSSL_64_BIT
 #define OPENSSL_MIPS64
+#elif defined(__riscv) && __SIZEOF_POINTER__ == 8
+#define OPENSSL_64_BIT
+#elif defined(__riscv) && __SIZEOF_POINTER__ == 4
+#define OPENSSL_32_BIT
 #elif defined(__pnacl__)
 #define OPENSSL_32_BIT
 #define OPENSSL_PNACL