diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,6 +13,7 @@
 include(ECMMarkAsTest)
 include(ECMPoQmTools)
 
+set(REQUIRED_QT_VERSION 5.12.0)
 find_package(Qt5 ${QT_REQUIRED_VERSION} CONFIG REQUIRED Core Gui Widgets Test)
 find_package(Boost REQUIRED)
 find_package(Threads REQUIRED)
diff --git a/src/presentation/taskfilterproxymodel.cpp b/src/presentation/taskfilterproxymodel.cpp
--- a/src/presentation/taskfilterproxymodel.cpp
+++ b/src/presentation/taskfilterproxymodel.cpp
@@ -21,6 +21,7 @@
    USA.
 */
 
+#include <QRegularExpression>
 
 #include "taskfilterproxymodel.h"
 
@@ -89,8 +90,8 @@
     const QModelIndex index = sourceModel()->index(sourceRow, 0, sourceParent);
     const auto task = index.data(QueryTreeModelBase::ObjectRole).value<Domain::Task::Ptr>();
     if (task) {
-        QRegExp regexp = filterRegExp();
-        regexp.setCaseSensitivity(Qt::CaseInsensitive);
+        QRegularExpression regexp = filterRegularExpression();
+        regexp.setPatternOptions(QRegularExpression::CaseInsensitiveOption);
 
         if (task->title().contains(regexp)
          || task->text().contains(regexp)) {
diff --git a/src/widgets/filterwidget.cpp b/src/widgets/filterwidget.cpp
--- a/src/widgets/filterwidget.cpp
+++ b/src/widgets/filterwidget.cpp
@@ -76,7 +76,7 @@
 
 void FilterWidget::onTextChanged(const QString &text)
 {
-    m_model->setFilterFixedString(text);
+    m_model->setFilterRegularExpression(QRegularExpression::escape(text));
 }
 
 void FilterWidget::onSortTypeChanged(int index)
diff --git a/src/widgets/quickselectdialog.cpp b/src/widgets/quickselectdialog.cpp
--- a/src/widgets/quickselectdialog.cpp
+++ b/src/widgets/quickselectdialog.cpp
@@ -89,15 +89,15 @@
     else
         m_label->setText(i18n("Path: %1", textFilter));
 
-    m_filterProxyModel->setFilterFixedString(textFilter);
+    m_filterProxyModel->setFilterRegularExpression(QRegularExpression::escape(textFilter));
     m_tree->expandAll();
 }
 
 bool QuickSelectDialog::eventFilter(QObject *, QEvent *ev)
 {
     if (ev->type() == QEvent::KeyPress) {
         auto event = static_cast<QKeyEvent*>(ev);
-        auto filter = m_filterProxyModel->filterRegExp().pattern();
+        auto filter = m_filterProxyModel->filterRegularExpression().pattern();
 
         switch (event->key()) {
         case Qt::Key_Backspace:
@@ -107,7 +107,7 @@
             filter = QString();
             break;
         default:
-            if (event->text().contains(QRegExp("^(\\w| )+$"))) {
+            if (event->text().contains(QRegularExpression(QStringLiteral("^(\\w| )+$")))) {
                 filter += event->text();
             }
             break;
diff --git a/tests/units/presentation/taskfilterproxymodeltest.cpp b/tests/units/presentation/taskfilterproxymodeltest.cpp
--- a/tests/units/presentation/taskfilterproxymodeltest.cpp
+++ b/tests/units/presentation/taskfilterproxymodeltest.cpp
@@ -83,7 +83,7 @@
         output.setSourceModel(&input);
 
         // WHEN
-        output.setFilterFixedString(QStringLiteral("find me"));
+        output.setFilterRegularExpression(QStringLiteral("find me"));
 
         // THEN
         QCOMPARE(output.rowCount(), 2);
@@ -139,7 +139,7 @@
         output.setSourceModel(&input);
 
         // WHEN
-        output.setFilterFixedString(QStringLiteral("find me"));
+        output.setFilterRegularExpression(QStringLiteral("find me"));
 
         // THEN
         QCOMPARE(output.rowCount(), 2);
diff --git a/tests/units/widgets/filterwidgettest.cpp b/tests/units/widgets/filterwidgettest.cpp
--- a/tests/units/widgets/filterwidgettest.cpp
+++ b/tests/units/widgets/filterwidgettest.cpp
@@ -44,7 +44,7 @@
 
         QVERIFY(filter.proxyModel());
         QVERIFY(!filter.proxyModel()->sourceModel());
-        QCOMPARE(filter.proxyModel()->filterRegExp(), QRegExp());
+        QCOMPARE(filter.proxyModel()->filterRegularExpression(), QRegularExpression());
         QCOMPARE(filter.proxyModel()->sortOrder(), Qt::AscendingOrder);
         QCOMPARE(filter.proxyModel()->sortType(), Presentation::TaskFilterProxyModel::TitleSort);
 
@@ -90,7 +90,7 @@
         QTest::keyClicks(filterEdit, QStringLiteral("find me"));
 
         // THEN
-        QCOMPARE(filter.proxyModel()->filterRegExp().pattern(), QStringLiteral("find me"));
+        QCOMPARE(filter.proxyModel()->filterRegularExpression().pattern(), QStringLiteral("find\\ me"));
     }
 
     void shouldClearFilter()
@@ -107,7 +107,7 @@
 
         // THEN
         QVERIFY(filterEdit->text().isEmpty());
-        QVERIFY(filter.proxyModel()->filterRegExp().pattern().isEmpty());
+        QVERIFY(filter.proxyModel()->filterRegularExpression().pattern().isEmpty());
     }
 
     void shouldShowExtension()
diff --git a/tests/units/widgets/pageviewtest.cpp b/tests/units/widgets/pageviewtest.cpp
--- a/tests/units/widgets/pageviewtest.cpp
+++ b/tests/units/widgets/pageviewtest.cpp
@@ -637,7 +637,7 @@
 
         QSortFilterProxyModel proxyModel;
         stubPageModel.setProxyModel(&proxyModel);
-        proxyModel.setFilterFixedString("B");
+        proxyModel.setFilterRegularExpression(QStringLiteral("B"));
 
         QPersistentModelIndex index = stubPageModel.centralListModel()->index(0, 0);
         QCOMPARE(index.data().toString(), QLatin1String("B"));