diff --git a/src/libs/extensionsystem/pluginview.cpp b/src/libs/extensionsystem/pluginview.cpp
index bf40d8d7f84..88a7350e403 100644
--- a/src/libs/extensionsystem/pluginview.cpp
+++ b/src/libs/extensionsystem/pluginview.cpp
@@ -315,7 +315,6 @@ PluginView::PluginView(QWidget *parent)
     m_sortModel = new CategorySortFilterModel(this);
     m_sortModel->setSourceModel(m_model);
     m_sortModel->setSortRole(SortRole);
-    m_sortModel->setFilterCaseSensitivity(Qt::CaseInsensitive);
     m_sortModel->setFilterKeyColumn(-1/*all*/);
     m_categoryView->setModel(m_sortModel);
 
@@ -357,7 +356,9 @@ PluginSpec *PluginView::currentPlugin() const
 */
 void PluginView::setFilter(const QString &filter)
 {
-    m_sortModel->setFilterFixedString(filter);
+    m_sortModel->setFilterRegularExpression(
+        QRegularExpression(QRegularExpression::escape(filter),
+                           QRegularExpression::CaseInsensitiveOption));
     m_categoryView->expandAll();
 }
 
diff --git a/src/plugins/cmakeprojectmanager/cmakebuildsettingswidget.cpp b/src/plugins/cmakeprojectmanager/cmakebuildsettingswidget.cpp
index a564bb12529..1baebfc8b4d 100644
--- a/src/plugins/cmakeprojectmanager/cmakebuildsettingswidget.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakebuildsettingswidget.cpp
@@ -153,7 +153,6 @@ CMakeBuildSettingsWidget::CMakeBuildSettingsWidget(CMakeBuildConfiguration *bc)
     m_configTextFilterModel->setSourceModel(m_configFilterModel);
     m_configTextFilterModel->setSortRole(Qt::DisplayRole);
     m_configTextFilterModel->setFilterKeyColumn(-1);
-    m_configTextFilterModel->setFilterCaseSensitivity(Qt::CaseInsensitive);
 
     connect(m_configTextFilterModel, &QAbstractItemModel::layoutChanged, this, [this]() {
         QModelIndex selectedIdx = m_configView->currentIndex();
@@ -271,8 +270,14 @@ CMakeBuildSettingsWidget::CMakeBuildSettingsWidget(CMakeBuildConfiguration *bc)
     connect(m_showAdvancedCheckBox, &QCheckBox::stateChanged,
             this, &CMakeBuildSettingsWidget::updateAdvancedCheckBox);
 
-    connect(m_filterEdit, &QLineEdit::textChanged,
-            m_configTextFilterModel, &QSortFilterProxyModel::setFilterFixedString);
+    connect(m_filterEdit,
+            &QLineEdit::textChanged,
+            m_configTextFilterModel,
+            [this](const QString &txt) {
+                m_configTextFilterModel->setFilterRegularExpression(
+                    QRegularExpression(QRegularExpression::escape(txt),
+                                       QRegularExpression::CaseInsensitiveOption));
+            });
 
     connect(m_resetButton, &QPushButton::clicked, m_configModel, &ConfigModel::resetAllChanges);
     connect(m_reconfigureButton,
diff --git a/src/plugins/coreplugin/locator/locatorsettingspage.cpp b/src/plugins/coreplugin/locator/locatorsettingspage.cpp
index 993bd84cc89..02ddbf6337c 100644
--- a/src/plugins/coreplugin/locator/locatorsettingspage.cpp
+++ b/src/plugins/coreplugin/locator/locatorsettingspage.cpp
@@ -190,7 +190,6 @@ public:
         m_proxyModel = new CategorySortFilterModel(m_ui.filterList);
         m_proxyModel->setSourceModel(m_model);
         m_proxyModel->setSortRole(SortRole);
-        m_proxyModel->setFilterCaseSensitivity(Qt::CaseInsensitive);
         m_proxyModel->setFilterKeyColumn(-1/*all*/);
         m_ui.filterList->setModel(m_proxyModel);
         m_ui.filterList->expandAll();
@@ -294,7 +293,9 @@ void LocatorSettingsWidget::requestRefresh()
 
 void LocatorSettingsWidget::setFilter(const QString &text)
 {
-    m_proxyModel->setFilterFixedString(text);
+    m_proxyModel->setFilterRegularExpression(
+        QRegularExpression(QRegularExpression::escape(text),
+                           QRegularExpression::CaseInsensitiveOption));
     m_ui.filterList->expandAll();
 }
 
diff --git a/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildsettingswidget.cpp b/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildsettingswidget.cpp
index df91c285fab..b8b35373b60 100644
--- a/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildsettingswidget.cpp
+++ b/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildsettingswidget.cpp
@@ -69,7 +69,6 @@ MesonBuildSettingsWidget::MesonBuildSettingsWidget(MesonBuildConfiguration *buil
     m_optionsFilter.setSourceModel(&m_optionsModel);
     m_optionsFilter.setSortRole(Qt::DisplayRole);
     m_optionsFilter.setFilterKeyColumn(-1);
-    m_optionsFilter.setFilterCaseSensitivity(Qt::CaseInsensitive);
 
     ui->optionsTreeView->setModel(&m_optionsFilter);
 
@@ -109,7 +108,11 @@ MesonBuildSettingsWidget::MesonBuildSettingsWidget(MesonBuildConfiguration *buil
     connect(ui->optionsFilterLineEdit,
             &QLineEdit::textChanged,
             &m_optionsFilter,
-            &QSortFilterProxyModel::setFilterFixedString);
+            [this](const QString &txt) {
+                m_optionsFilter.setFilterRegularExpression(
+                    QRegularExpression(QRegularExpression::escape(txt),
+                                       QRegularExpression::CaseInsensitiveOption));
+            });
     connect(ui->optionsTreeView,
             &Utils::TreeView::activated,
             ui->optionsTreeView,