diff --git a/src/lhisp-oauth-client.ts b/src/lhisp-oauth-client.ts
index 3075eed..f8ddcb0 100644
--- a/src/lhisp-oauth-client.ts
+++ b/src/lhisp-oauth-client.ts
@@ -41,7 +41,7 @@ export class LhispOauthClient<iAccessToken extends AccessToken = AccessToken> {
     if (params.certificado) {
       this.agent = new https.Agent({
         pfx: Buffer.isBuffer(params.certificado) ? params.certificado : Buffer.from(params.certificado, "base64"),
-        passphrase: params.senhaCertificado,
+        passphrase: params.senhaCertificado ? params.senhaCertificado : undefined,
         rejectUnauthorized: false,
       });
     } else {