diff --git a/src/backends/scilab/scilabhighlighter.cpp b/src/backends/scilab/scilabhighlighter.cpp
index 73748365..d323ea5f 100644
--- a/src/backends/scilab/scilabhighlighter.cpp
+++ b/src/backends/scilab/scilabhighlighter.cpp
@@ -1,84 +1,83 @@
 /*
     This program is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
     as published by the Free Software Foundation; either version 2
     of the License, or (at your option) any later version.
 
     This program 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 General Public License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA  02110-1301, USA.
 
     ---
     Copyright (C) 2011 Filipe Saraiva <filipe@kde.org>
  */
 
 #include "scilabhighlighter.h"
 #include "scilabkeywords.h"
 #include "result.h"
 #include "textresult.h"
 #include "session.h"
 
 #include <QTextEdit>
 #include <QDebug>
 
 ScilabHighlighter::ScilabHighlighter(QObject* parent, Cantor::Session* session) : Cantor::DefaultHighlighter(parent), m_session(session)
 {
     addKeywords(ScilabKeywords::instance()->keywords());
     addFunctions(ScilabKeywords::instance()->functions());
     addVariables(ScilabKeywords::instance()->variables());
 
     addRule(QRegularExpression(QStringLiteral("\\b[A-Za-z0-9_]+(?=\\()")), functionFormat());
 
     addRule(QLatin1String("FIXME"), commentFormat());
     addRule(QLatin1String("TODO"), commentFormat());
 
     addRule(QRegularExpression(QStringLiteral("\"[^\"]*\"")), stringFormat());
     addRule(QRegularExpression(QStringLiteral("'[^']*'")), stringFormat());
     addRule(QRegularExpression(QStringLiteral("//[^\n]*")), commentFormat());
 
-    commentStartExpression = QRegExp(QLatin1String("/\\*"));
-    commentEndExpression = QRegExp(QLatin1String("\\*/"));
+    commentStartExpression = QRegularExpression(QStringLiteral("/\\*"));
+    commentEndExpression = QRegularExpression(QStringLiteral("\\*/"));
 }
 
 void ScilabHighlighter::highlightBlock(const QString& text)
 {
     if (skipHighlighting(text)){
         return;
     }
 
     //Do some backend independent highlighting (brackets etc.)
     DefaultHighlighter::highlightBlock(text);
 
     setCurrentBlockState(0);
 
     int startIndex = 0;
     if (previousBlockState() != 1)
-        startIndex = commentStartExpression.indexIn(text);
+        startIndex = text.indexOf(commentStartExpression);
 
     while (startIndex >= 0){
-
-        int endIndex = commentEndExpression.indexIn(text, startIndex);
+        QRegularExpressionMatch endMatch;
+        const int endIndex = text.indexOf(commentEndExpression, startIndex, &endMatch);
         int commentLength;
-        if (endIndex == -1){
-
+        if (endIndex == -1) { // no match found
             setCurrentBlockState(1);
             commentLength = text.length() - startIndex;
-        } else {
-            commentLength = endIndex - startIndex
-                + commentEndExpression.matchedLength();
+        } else { // match found
+            // endMatch.catpuredEnd(0) is endIndex + endMatch.capturedLength(0)
+            commentLength = endMatch.capturedEnd(0) - startIndex;
         }
         setFormat(startIndex,  commentLength,  commentFormat());
-        startIndex = commentStartExpression.indexIn(text,  startIndex + commentLength);
+        startIndex = text.indexOf(commentStartExpression, startIndex + commentLength);
     }
 }
 
 QString ScilabHighlighter::nonSeparatingCharacters() const
 {
     return QLatin1String("[%]");
 }
diff --git a/src/backends/scilab/scilabhighlighter.h b/src/backends/scilab/scilabhighlighter.h
index 20cbdfdb..21d8a474 100644
--- a/src/backends/scilab/scilabhighlighter.h
+++ b/src/backends/scilab/scilabhighlighter.h
@@ -1,45 +1,47 @@
 /*
     This program is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
     as published by the Free Software Foundation; either version 2
     of the License, or (at your option) any later version.
 
     This program 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 General Public License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA  02110-1301, USA.
 
     ---
     Copyright (C) 2011 Filipe Saraiva <filipe@kde.org>
  */
 
 #ifndef _SCILABHIGHLIGHTER_H
 #define _SCILABHIGHLIGHTER_H
 
+#include <QRegularExpression>
+
 #include "defaulthighlighter.h"
 #include "scilabexpression.h"
 
 class ScilabHighlighter : public Cantor::DefaultHighlighter
 {
     Q_OBJECT
 
     public:
         ScilabHighlighter(QObject* parent, Cantor::Session* session);
         ~ScilabHighlighter() override = default;
 
     protected:
         void highlightBlock(const QString&) override;
         QString nonSeparatingCharacters() const override;
 
     private:
         Cantor::Session* m_session;
-        QRegExp commentStartExpression;
-        QRegExp commentEndExpression;
+        QRegularExpression commentStartExpression;
+        QRegularExpression commentEndExpression;
 };
 
 #endif /* _SCILABHIGHLIGHTER_H */