diff --git a/crypto/cmp/cmp_kem.c b/crypto/cmp/cmp_kem.c
index c265bd4b3a040..7503e903d3ec6 100644
--- a/crypto/cmp/cmp_kem.c
+++ b/crypto/cmp/cmp_kem.c
@@ -71,6 +71,8 @@ X509_ALGOR *ossl_cmp_kem_kdf_algor(int nid_kdf, OSSL_LIB_CTX *libctx,
             return NULL;
         (void)x509_algor_from_nid_with_md(NID_id_kdf_kdf2, &alg, md);
         EVP_MD_free(md);
+    } else if (nid_kdf == NID_shake256) {
+        alg = ossl_X509_ALGOR_from_nid(NID_shake256, V_ASN1_UNDEF, NULL);
     } else {
         ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_ALGORITHM);
     }
@@ -281,6 +283,47 @@ int ossl_cmp_kem_performKemDecapsulation(EVP_PKEY *pkey,
     return 0;
 }
 
+int ossl_cmp_kem_derive_ssk_SHAKE256(unsigned char *key, int keylen,
+                                     unsigned char *salt, int saltlen,
+                                     unsigned char *info, int infolen,
+                                     unsigned char **ssk, int ssklen,
+                                     OSSL_LIB_CTX *libctx, char *propq)
+{
+    EVP_MD_CTX *hashctx = NULL;
+    EVP_MD *shake256 = NULL;
+    int ret = 0;
+
+    if (ssk == NULL || key == NULL)
+        return 0;
+
+    *ssk = OPENSSL_zalloc(ssklen);
+    hashctx = EVP_MD_CTX_new();
+    shake256 = EVP_MD_fetch(libctx, "SHAKE256", propq);
+    if (*ssk == NULL || hashctx == NULL || shake256 == NULL)
+        goto err;
+
+    if (!EVP_DigestInit_ex(hashctx, shake256, NULL)
+            || !EVP_DigestUpdate(hashctx, key, keylen)
+            || !EVP_DigestUpdate(hashctx, salt, saltlen)
+            || !EVP_DigestUpdate(hashctx, info, infolen)
+            || !EVP_DigestFinalXOF(hashctx, *ssk, ssklen))
+        goto err;
+
+    ret = 1;
+ err:
+    if (!ret)
+        OPENSSL_clear_free(*ssk, ssklen);
+    EVP_MD_CTX_free(hashctx);
+    EVP_MD_free(shake256);
+
+    printf("\n SHAKE256 ");
+    print_buf("\nKEY", key, keylen);
+    print_buf("\ninfo", info, infolen);
+    print_buf("\nssk", *ssk, ssklen);
+
+    return ret;
+}
+
 int ossl_cmp_kem_derive_ssk_HKDF(unsigned char *key, int keylen,
                                  unsigned char *salt, int saltlen,
                                  unsigned char *info, int infolen,
diff --git a/crypto/cms/cms_env.c b/crypto/cms/cms_env.c
index 9a860ba7faa1c..afe462995d098 100644
--- a/crypto/cms/cms_env.c
+++ b/crypto/cms/cms_env.c
@@ -404,7 +404,7 @@ static int cms_RecipientInfo_kemri_init(CMS_RecipientInfo *ri, X509 *recip,
                                      ossl_cmp_kem_algor(pk, ctx->libctx,
                                                         ctx->propq))
         || !ossl_cmp_x509_algor_set0(&kemri->kdf,
-                                     ossl_cmp_kem_kdf_algor(NID_hkdfWithSHA256,
+                                     ossl_cmp_kem_kdf_algor(NID_shake256,
                                                             ctx->libctx,
                                                             ctx->propq))
         || !ASN1_INTEGER_set(kemri->kekLength, 32)) /* hard code for testing*/
@@ -418,7 +418,7 @@ static int cms_RecipientInfo_kemri_init(CMS_RecipientInfo *ri, X509 *recip,
     if (!cms_ORIforKEMOtherInfo_new(kemri, &info, &infolen))
         goto err;
 
-    if (!ossl_cmp_kem_derive_ssk_HKDF(ss, sslen, NULL, 0, info, infolen,
+    if (!ossl_cmp_kem_derive_ssk_SHAKE256(ss, sslen, NULL, 0, info, infolen,
                                      &kemri->secret, kemri->secret_len,
                                      ctx->libctx, ctx->propq))
         goto err;
diff --git a/crypto/cms/cms_smime.c b/crypto/cms/cms_smime.c
index d5e9d99b6fb88..f904807e9af71 100644
--- a/crypto/cms/cms_smime.c
+++ b/crypto/cms/cms_smime.c
@@ -711,7 +711,7 @@ static int cms_kemri_set1_pkey(CMS_ContentInfo *cms,
                                          &ss, &sslen,
                                          cms->ctx.libctx, cms->ctx.propq)
         || !cms_ORIforKEMOtherInfo_new(kemri, &info, &infolen)
-        || !ossl_cmp_kem_derive_ssk_HKDF(ss, sslen, NULL, 0, info, infolen,
+        || !ossl_cmp_kem_derive_ssk_SHAKE256(ss, sslen, NULL, 0, info, infolen,
                                          &kemri->secret,
                                          ASN1_INTEGER_get(kemri->kekLength),
                                          cms->ctx.libctx, cms->ctx.propq))
diff --git a/include/internal/cmp.h b/include/internal/cmp.h
index c471af974ff66..53717db03c7c2 100644
--- a/include/internal/cmp.h
+++ b/include/internal/cmp.h
@@ -40,5 +40,10 @@ int ossl_cmp_kem_derive_ssk_HKDF(unsigned char *key, int keylen,
                                  unsigned char *info, int infolen,
                                  unsigned char **ssk, int ssklen,
                                  OSSL_LIB_CTX *libctx, char *propq);
+int ossl_cmp_kem_derive_ssk_SHAKE256(unsigned char *key, int keylen,
+                                     unsigned char *salt, int saltlen,
+                                     unsigned char *info, int infolen,
+                                     unsigned char **ssk, int ssklen,
+                                     OSSL_LIB_CTX *libctx, char *propq);
 
 #endif