diff --git a/src/limitedcharlineedit.cpp b/src/limitedcharlineedit.cpp
index 6aa4adb..ad16ded 100644
--- a/src/limitedcharlineedit.cpp
+++ b/src/limitedcharlineedit.cpp
@@ -1,80 +1,81 @@
 /*
  *  Copyright (c) 2002-2003 Jesper K. Pedersen <blackie@kde.org>
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License version 2 as published by the Free Software Foundation.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Library General Public License for more details.
  *
  *  You should have received a copy of the GNU Library General Public License
  *  along with this library; see the file COPYING.LIB.  If not, write to
  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  *  Boston, MA 02110-1301, USA.
  **/
 
 #include "limitedcharlineedit.h"
 
 #include <QValidator>
 #include <QKeyEvent>
+#include <QRegularExpression>
 
 /**
    @internal
    A Validator for the @ref LimitedCharLineEdit
 */
 class Validator : public QValidator
 {
 public:
     Validator(LimitedCharLineEdit::Mode mode, QWidget *parent)
         : QValidator(parent)
         , _mode(mode)
     {
         setObjectName(QStringLiteral("Validator"));
     }
 
     QValidator::State validate(QString &txt, int & /*pos*/) const override
     {
         if (_mode == LimitedCharLineEdit::NORMAL
             || (_mode == LimitedCharLineEdit::HEX
-                && QRegExp(QStringLiteral("^[0-9A-Fa-f]*$")).indexIn(txt) != -1)
+                && txt.contains(QRegularExpression(QStringLiteral("^[0-9A-Fa-f]*$"))))
             || (_mode == LimitedCharLineEdit::OCT
-                && QRegExp(QStringLiteral("^[0-7]*$")).indexIn(txt) != -1)) {
+                && txt.contains(QRegularExpression(QStringLiteral("^[0-7]*$"))))) {
             return QValidator::Acceptable;
         } else {
             return QValidator::Invalid;
         }
     }
 
 private:
     LimitedCharLineEdit::Mode _mode;
 };
 
 void LimitedCharLineEdit::keyPressEvent(QKeyEvent *event)
 {
     QLineEdit::keyPressEvent(event);
     if (text().length() == _count && !event->text().isNull()) {
         focusNextPrevChild(true);
     }
 }
 
 LimitedCharLineEdit::LimitedCharLineEdit(Mode mode, QWidget *parent, const QString &name)
     : QLineEdit(parent)
 {
     setObjectName(name);
 
     if (mode == NORMAL) {
         _count = 1;
     } else if (mode == HEX) {
         _count = 4;
     } else {
         _count = 4;
     }
 
     setMaxLength(_count);
     setFixedSize(fontMetrics().boundingRect(QLatin1Char('A')).width() * 5 + 5, sizeHint().height());
 
     setValidator(new Validator(mode, this));
 }