diff --git a/ext/openssl/openssl.c b/ext/openssl/openssl.c
index e514ebeeaba59..2a502f20688cc 100644
--- a/ext/openssl/openssl.c
+++ b/ext/openssl/openssl.c
@@ -2552,6 +2552,9 @@ static STACK_OF(X509) *php_array_to_X509_sk(zval * zcerts, uint32_t arg_num, con
 	bool free_cert;
 
 	sk = sk_X509_new_null();
+	if (sk == NULL) {
+		goto clean_exit;
+	}
 
 	/* get certs */
 	if (Z_TYPE_P(zcerts) == IS_ARRAY) {
@@ -5797,6 +5800,9 @@ PHP_FUNCTION(openssl_pkcs7_encrypt)
 	}
 
 	recipcerts = sk_X509_new_null();
+	if (recipcerts == NULL) {
+		goto clean_exit;
+	}
 
 	/* get certs */
 	if (Z_TYPE_P(zrecipcerts) == IS_ARRAY) {
@@ -6404,6 +6410,9 @@ PHP_FUNCTION(openssl_cms_encrypt)
 	}
 
 	recipcerts = sk_X509_new_null();
+	if (recipcerts == NULL) {
+		goto clean_exit;
+	}
 
 	/* get certs */
 	if (Z_TYPE_P(zrecipcerts) == IS_ARRAY) {