diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 6bb462042..1a9ea7179 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -24,6 +24,7 @@ jobs:
         repo: open-eid/libdigidocpp
     - name: Install dependencies
       run: |
+        brew install ninja
         HASH=($(shasum prepare_osx_build_environment.sh))
         curl -O -L -s https://installer.id.ee/media/github/opensc_0.22.0.pkg
         curl -O -L -s https://installer.id.ee/media/github/${HASH}.zip
@@ -33,7 +34,7 @@ jobs:
     - name: Build
       run: |
         QT_DIR=$(ls -d /Library/Developer/Qt-*-OpenSSL | tail -n 1)
-        cmake \
+        cmake "-GNinja" \
           -DCMAKE_PREFIX_PATH=${QT_DIR} \
           -DOPENSSL_ROOT_DIR=/Library/Developer/OpenSSL \
           -DLDAP_ROOT=/Library/Developer/OpenLDAP \
@@ -61,7 +62,11 @@ jobs:
       with:
         submodules: recursive
     - name: Install dependencies
+      if: matrix.container != 'ubuntu:22.04'
       run: apt update -qq && apt install --no-install-recommends -y lsb-release fakeroot build-essential devscripts cdbs pkg-config cmake libldap2-dev gettext libpcsclite-dev libssl-dev libqt5svg5-dev qttools5-dev-tools qttools5-dev lintian
+    - name: Install dependencies
+      if: matrix.container == 'ubuntu:22.04'
+      run: apt update -qq && apt install --no-install-recommends -y lsb-release fakeroot build-essential devscripts cdbs pkg-config cmake libldap2-dev gettext libpcsclite-dev libssl-dev libgl-dev libqt6svg6-dev qt6-tools-dev qt6-tools-dev-tools qt6-l10n-tools libqt6core5compat6-dev lintian
     - name: Download artifact
       uses: dawidd6/action-download-artifact@v2
       with:
@@ -105,7 +110,11 @@ jobs:
       with:
         submodules: recursive
     - name: Install Deps
+      if: matrix.container == 'fedora:35'
       run: dnf install -y gcc-c++ cmake rpm-build gettext openssl-devel openldap-devel pcsc-lite-devel qt5-qtsvg-devel qt5-linguist
+    - name: Install Deps
+      if: matrix.container != 'fedora:35'
+      run: dnf install -y gcc-c++ cmake rpm-build gettext openssl-devel openldap-devel pcsc-lite-devel qt6-qtsvg-devel qt6-qttools-devel qt6-qt5compat-devel
     - name: Download artifact
       uses: dawidd6/action-download-artifact@v2
       with:
diff --git a/client/Application.cpp b/client/Application.cpp
index 2ec7bae17..c2bbee094 100644
--- a/client/Application.cpp
+++ b/client/Application.cpp
@@ -51,6 +51,7 @@ class MacMenuBar {};
 #include <QtCore/QJsonDocument>
 #include <QtCore/QJsonObject>
 #include <QtCore/QProcess>
+#include <QtCore/QRegularExpression>
 #include <QtCore/QSettings>
 #include <QtCore/QStandardPaths>
 #include <QtCore/QTimer>
@@ -722,7 +723,7 @@ void Application::mailTo( const QUrl &url )
 	QByteArray thunderbird;
 	QProcess p;
 	QStringList env = QProcess::systemEnvironment();
-	if( env.indexOf( QRegExp("KDE_FULL_SESSION.*") ) != -1 )
+	if(env.indexOf(QRegularExpression(QStringLiteral("KDE_FULL_SESSION.*"))) != -1)
 	{
 		p.start("kreadconfig", {
 			"--file", "emaildefaults",
@@ -733,7 +734,7 @@ void Application::mailTo( const QUrl &url )
 		if( data.contains("thunderbird") )
 			thunderbird = data;
 	}
-	else if( env.indexOf( QRegExp("GNOME_DESKTOP_SESSION_ID.*") ) != -1 )
+	else if(env.indexOf(QRegularExpression(QStringLiteral("GNOME_DESKTOP_SESSION_ID.*"))) != -1)
 	{
 		if(QSettings(QDir::homePath() + "/.local/share/applications/mimeapps.list", QSettings::IniFormat)
 				.value("Default Applications/x-scheme-handler/mailto").toString().contains("thunderbird"))
diff --git a/client/Diagnostics_unix.cpp b/client/Diagnostics_unix.cpp
index da6f81616..fee099c38 100644
--- a/client/Diagnostics_unix.cpp
+++ b/client/Diagnostics_unix.cpp
@@ -22,6 +22,7 @@
 #include "Common.h"
 
 #include <QtCore/QFile>
+#include <QtCore/QRegularExpression>
 #include <QtCore/QTextStream>
 #include <QtCore/QProcess>
 #include <QtNetwork/QSslSocket>
@@ -102,10 +103,11 @@ void Diagnostics::run()
 	QFile f( "/proc/cpuinfo" );
 	if( f.open( QFile::ReadOnly ) )
 	{
-		QRegExp rx( "model name.*\\: (.*)\n" );
-		rx.setMinimal( true );
-		if( rx.indexIn( QString::fromLocal8Bit( f.readAll() ) ) != -1 )
-			s << rx.cap( 1 );
+		QRegularExpression rx(QStringLiteral("model name.*\\: (.*)\n"));
+		rx.setPatternOptions(QRegularExpression::InvertedGreedinessOption);
+		QRegularExpressionMatch match = rx.match(QString::fromLocal8Bit(f.readAll()));
+		if(match.hasMatch())
+			s << match.captured(1);
 	}
 	s << "<br />";
 #endif
diff --git a/debian/control b/debian/control
index 46588010d..1526511c1 100644
--- a/debian/control
+++ b/debian/control
@@ -10,8 +10,9 @@ Build-Depends:
  libldap2-dev,
  libpcsclite-dev,
  libssl-dev,
- qttools5-dev,
- libqt5svg5-dev
+ qt6-tools-dev | qttools5-dev,
+ qt6-l10n-tools | qttools5-dev-tools,
+ libqt6svg6-dev | libqt5svg5-dev
 Standards-Version: 3.9.8
 Homepage: https://github.com/open-eid/DigiDoc4-Client
 
@@ -20,6 +21,7 @@ Architecture: any
 Depends:
  opensc-pkcs11,
  python3-nautilus|python-nautilus,
+ qt6-qpa-plugins | libqt5gui5,
  ${shlibs:Depends},
  ${misc:Depends}
 Replaces: