diff --git a/src/crypto/sha3/sha3_c.c b/src/crypto/sha3/sha3_c.c
index ef9515476..4968cd914 100644
--- a/src/crypto/sha3/sha3_c.c
+++ b/src/crypto/sha3/sha3_c.c
@@ -21,7 +21,11 @@
 #define sha3_256_inc_finalize OQS_SHA3_sha3_256_inc_finalize
 
 #define SHA3_384_RATE OQS_SHA3_SHA3_384_RATE
+#ifndef USE_SHA3_OPENSSL
 #define sha3_384 OQS_SHA3_sha3_384
+#else
+#define sha3_384 oqs_unused_SHA3_sha3_384
+#endif
 
 #define sha3_384incctx OQS_SHA3_sha3_384_inc_ctx
 #define sha3_384_inc_init OQS_SHA3_sha3_384_inc_init
@@ -29,7 +33,11 @@
 #define sha3_384_inc_finalize OQS_SHA3_sha3_384_inc_finalize
 
 #define SHA3_512_RATE OQS_SHA3_SHA3_512_RATE
+#ifndef USE_SHA3_OPENSSL
 #define sha3_512 OQS_SHA3_sha3_512
+#else
+#define sha3_512 oqs_unused_SHA3_sha3_512
+#endif
 
 #define sha3_512incctx OQS_SHA3_sha3_512_inc_ctx
 #define sha3_512_inc_init OQS_SHA3_sha3_512_inc_init
@@ -37,7 +45,11 @@
 #define sha3_512_inc_finalize OQS_SHA3_sha3_512_inc_finalize
 
 #define SHAKE128_RATE OQS_SHA3_SHAKE128_RATE
+#ifndef USE_SHA3_OPENSSL
 #define shake128 OQS_SHA3_shake128
+#else
+#define shake128 oqs_unused_SHA3_shake128
+#endif
 
 #define shake128ctx OQS_SHA3_shake128_ctx
 #define shake128_absorb OQS_SHA3_shake128_absorb
@@ -50,7 +62,11 @@
 #define shake128_inc_squeeze OQS_SHA3_shake128_inc_squeeze
 
 #define SHAKE256_RATE OQS_SHA3_SHAKE256_RATE
+#ifndef USE_SHA3_OPENSSL
 #define shake256 OQS_SHA3_shake256
+#else
+#define shake256 oqs_unused_SHA3_shake256
+#endif
 
 #define shake256ctx OQS_SHA3_shake256_ctx
 #define shake256_absorb OQS_SHA3_shake256_absorb
diff --git a/src/crypto/sha3/sha3_ossl.c b/src/crypto/sha3/sha3_ossl.c
index d30cdb18d..1fc89abdb 100644
--- a/src/crypto/sha3/sha3_ossl.c
+++ b/src/crypto/sha3/sha3_ossl.c
@@ -21,10 +21,43 @@ static void do_hash(uint8_t *output, const uint8_t *input, size_t inplen, const
 	EVP_MD_CTX_destroy(mdctx);
 }
 
+static void do_xof(uint8_t *output, size_t outlen, const uint8_t *input, size_t inplen, const EVP_MD *md) {
+	EVP_MD_CTX *mdctx;
+	mdctx = EVP_MD_CTX_create();
+	EVP_DigestInit_ex(mdctx, md, NULL);
+	EVP_DigestUpdate(mdctx, input, inplen);
+	EVP_DigestFinalXOF(mdctx, output, outlen);
+	EVP_MD_CTX_destroy(mdctx);
+}
+
 void OQS_SHA3_sha3_256(uint8_t *output, const uint8_t *input, size_t inplen) {
 	const EVP_MD *md;
 	md = EVP_sha3_256();
 	do_hash(output, input, inplen, md);
 }
 
+void OQS_SHA3_sha3_384(uint8_t *output, const uint8_t *input, size_t inplen) {
+	const EVP_MD *md;
+	md = EVP_sha3_384();
+	do_hash(output, input, inplen, md);
+}
+
+void OQS_SHA3_sha3_512(uint8_t *output, const uint8_t *input, size_t inplen) {
+	const EVP_MD *md;
+	md = EVP_sha3_512();
+	do_hash(output, input, inplen, md);
+}
+
+void OQS_SHA3_shake128(uint8_t *output, size_t outlen, const uint8_t *input, size_t inplen) {
+	const EVP_MD *md;
+	md = EVP_shake128();
+	do_xof(output, outlen, input, inplen, md);
+}
+
+void OQS_SHA3_shake256(uint8_t *output, size_t outlen, const uint8_t *input, size_t inplen) {
+	const EVP_MD *md;
+	md = EVP_shake256();
+	do_xof(output, outlen, input, inplen, md);
+}
+
 #endif