diff --git a/generator/config/CustomPhpStanFunctionMap.php b/generator/config/CustomPhpStanFunctionMap.php
index 241488ec..b8b675d8 100644
--- a/generator/config/CustomPhpStanFunctionMap.php
+++ b/generator/config/CustomPhpStanFunctionMap.php
@@ -30,6 +30,7 @@
     'openssl_pkey_get_details' => ['array|false', 'key'=>'OpenSSLAsymmetricKey'],
     'openssl_pkey_get_private' => ['OpenSSLAsymmetricKey|false', 'private_key'=>'OpenSSLAsymmetricKey|OpenSSLCertificate|array|string', 'passphrase='=>'null|string'],
     'openssl_pkey_get_public' => ['OpenSSLAsymmetricKey|false', 'public_key'=>'OpenSSLAsymmetricKey|OpenSSLCertificate|array|string'],
+    'openssl_sign' => ['void', 'data'=>'string', '&signature'=>'string|null', 'private_key'=>'OpenSSLAsymmetricKey|resource|string', 'algorithm'=>'int|string'],
     // theses replace ressource by OpenSSLCertificate
     'openssl_verify' => ['-1|0|1|false', 'data'=>'string', 'signature'=>'string', 'pub_key_id'=>' OpenSSLAsymmetricKey|OpenSSLCertificate|string', 'signature_alg='=>'int|string'],
     'openssl_x509_read' => ['OpenSSLCertificate|false', 'x509certdata'=>'OpenSSLCertificate|string'], // this replaces ressource by OpenSSLCertificate