diff --git a/src/compat.cpp b/src/compat.cpp
--- a/src/compat.cpp
+++ b/src/compat.cpp
@@ -37,7 +37,7 @@
 
 #include "kcalendarcore_debug.h"
 
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QString>
 #include <QDate>
 
@@ -54,7 +54,7 @@
     if (korg >= 0) {
         int versionStart = productId.indexOf(QLatin1Char(' '), korg);
         if (versionStart >= 0) {
-            int versionStop = productId.indexOf(QRegExp(QStringLiteral("[ /]")), versionStart + 1);
+            int versionStop = productId.indexOf(QRegularExpression(QStringLiteral("[ /]")), versionStart + 1);
             if (versionStop >= 0) {
                 QString version = productId.mid(versionStart + 1,
                                                 versionStop - versionStart - 1);
@@ -117,7 +117,7 @@
     if (incidence->summary().isEmpty() && !(incidence->description().isEmpty())) {
         QString oldDescription = incidence->description().trimmed();
         QString newSummary(oldDescription);
-        newSummary.remove(QRegExp(QStringLiteral("\n.*")));
+        newSummary.remove(QRegularExpression(QStringLiteral("\n.*")));
         incidence->setSummary(newSummary);
         if (oldDescription == newSummary) {
             incidence->setDescription(QLatin1String(""));
diff --git a/src/person.cpp b/src/person.cpp
--- a/src/person.cpp
+++ b/src/person.cpp
@@ -35,8 +35,9 @@
 
 #include "person.h"
 #include "person_p.h"
-#include <QRegExp>
+
 #include <QDataStream>
+#include <QRegularExpression>
 
 using namespace KCalendarCore;
 
@@ -104,7 +105,7 @@
     }
     // Taken from KContacts::Addressee::fullEmail
     QString fullName = name;
-    QRegExp needQuotes(QStringLiteral("[^ 0-9A-Za-z\\x0080-\\xFFFF]"));
+    const QRegularExpression needQuotes(QStringLiteral("[^ 0-9A-Za-z\\x{0080}-\\x{FFFF}]"));
     bool weNeedToQuote = name.indexOf(needQuotes) != -1;
     if (weNeedToQuote) {
         if (fullName[0] != QLatin1Char('"')) {