diff --git a/src/smtpclient.cpp b/src/smtpclient.cpp
index cbbcd5f..39cd786 100644
--- a/src/smtpclient.cpp
+++ b/src/smtpclient.cpp
@@ -617,6 +617,8 @@ void SmtpClient::socketStateChanged(QAbstractSocket::SocketState state) {
 void SmtpClient::socketError(QAbstractSocket::SocketError socketError) {
 #ifndef QT_NO_DEBUG
     qDebug() << "SocketError:" << socketError << socket->error();
+#else
+    Q_UNUSED(socketError);
 #endif
     emit error(SocketError);
 }