diff --git a/ext/openssl/ossl_pkey_dh.c b/ext/openssl/ossl_pkey_dh.c
index 3f2975c5a..558bc56bf 100644
--- a/ext/openssl/ossl_pkey_dh.c
+++ b/ext/openssl/ossl_pkey_dh.c
@@ -141,7 +141,8 @@ static VALUE
 ossl_dh_initialize_copy(VALUE self, VALUE other)
 {
     EVP_PKEY *pkey;
-    DH *dh, *dh_other;
+    DH *dh;
+    OSSL_3_const DH *dh_other;
     const BIGNUM *pub, *priv;
 
     TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
@@ -318,7 +319,7 @@ ossl_dh_check_params(VALUE self)
     ret = EVP_PKEY_param_check(pctx);
     EVP_PKEY_CTX_free(pctx);
 #else
-    DH *dh;
+    OSSL_3_const DH *dh;
     int codes;
 
     GetDH(self, dh);
diff --git a/ext/openssl/ossl_pkey_dsa.c b/ext/openssl/ossl_pkey_dsa.c
index 041646a05..0ef1c43f4 100644
--- a/ext/openssl/ossl_pkey_dsa.c
+++ b/ext/openssl/ossl_pkey_dsa.c
@@ -152,7 +152,8 @@ static VALUE
 ossl_dsa_initialize_copy(VALUE self, VALUE other)
 {
     EVP_PKEY *pkey;
-    DSA *dsa, *dsa_new;
+    OSSL_3_const DSA *dsa;
+    DSA *dsa_new;
 
     TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
     if (pkey)
diff --git a/ext/openssl/ossl_pkey_ec.c b/ext/openssl/ossl_pkey_ec.c
index 35f031819..bd9647677 100644
--- a/ext/openssl/ossl_pkey_ec.c
+++ b/ext/openssl/ossl_pkey_ec.c
@@ -199,7 +199,8 @@ static VALUE
 ossl_ec_key_initialize_copy(VALUE self, VALUE other)
 {
     EVP_PKEY *pkey;
-    EC_KEY *ec, *ec_new;
+    OSSL_3_const EC_KEY *ec;
+    EC_KEY *ec_new;
 
     TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
     if (pkey)
@@ -566,7 +567,7 @@ static VALUE ossl_ec_key_check_key(VALUE self)
 
     EVP_PKEY_CTX_free(pctx);
 #else
-    EC_KEY *ec;
+    OSSL_3_const EC_KEY *ec;
 
     GetEC(self, ec);
     if (EC_KEY_check_key(ec) != 1)
diff --git a/ext/openssl/ossl_pkey_rsa.c b/ext/openssl/ossl_pkey_rsa.c
index 039b2c6a3..7af0e2209 100644
--- a/ext/openssl/ossl_pkey_rsa.c
+++ b/ext/openssl/ossl_pkey_rsa.c
@@ -148,7 +148,8 @@ static VALUE
 ossl_rsa_initialize_copy(VALUE self, VALUE other)
 {
     EVP_PKEY *pkey;
-    RSA *rsa, *rsa_new;
+    OSSL_3_const RSA *rsa;
+    RSA *rsa_new;
 
     TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
     if (pkey)