diff --git a/CMakeLists.txt b/CMakeLists.txt
index cec28d0f..d72eb6a9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -25,7 +25,7 @@ set(CMAKE_OSX_DEPLOYMENT_TARGET 10.13)
 
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
-set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 set(CMAKE_AUTOMOC ON)
@@ -49,15 +49,15 @@ if (APPLE)
   execute_process(COMMAND brew --prefix OUTPUT_STRIP_TRAILING_WHITESPACE
                   OUTPUT_VARIABLE BREW_PREFIX ERROR_QUIET)
   # Preset the default brew paths....
-  if (NOT Qt5_DIR)
-    set(Qt5_DIR ${BREW_PREFIX}/opt/qt@5/lib/cmake/Qt5)
+  if (NOT CMAKE_PREFIX_PATH)
+    set(CMAKE_PREFIX_PATH ${BREW_PREFIX}/opt/qt@5/)
   endif()
   if (NOT OPENSSL_ROOT_DIR)
     set(OPENSSL_ROOT_DIR ${BREW_PREFIX}/opt/openssl@1.1)
   endif()
 elseif(WIN32)
-  if (NOT Qt5_DIR)
-    set(Qt5_DIR "C:/Qt/5.15.2/mingw81_64/lib/cmake/Qt5")
+  if (NOT CMAKE_PREFIX_PATH)
+    set(CMAKE_PREFIX_PATH "C:/Qt/5.15.2/mingw81_64/")
   endif()
   if (NOT OPENSSL_ROOT_DIR)
     set(OPENSSL_ROOT_DIR $ENV{PROGRAMFILES}/OpenSSL-Win64)
@@ -75,13 +75,18 @@ elseif(WIN32)
   file(TO_CMAKE_PATH $ENV{WINDIR}/system32 SYSTEM32)
 endif()
 file(TO_CMAKE_PATH "${OPENSSL_ROOT_DIR}" OPENSSL_ROOT_DIR)
-file(TO_CMAKE_PATH "${Qt5_DIR}" Qt5_DIR)
 file(TO_CMAKE_PATH "${PSQL_BINDIR}" PSQL_BINDIR)
 file(TO_CMAKE_PATH "${MYSQL_BINDIR}" MYSQL_BINDIR)
 
 find_package(OpenSSL REQUIRED)
-find_package(Qt5 REQUIRED COMPONENTS Core Widgets Sql Help LinguistTools)
-get_target_property(qmake_executable Qt5::qmake IMPORTED_LOCATION)
+find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Core)
+set(QT Qt${QT_VERSION_MAJOR})
+find_package(${QT} REQUIRED COMPONENTS Core Widgets Sql Help LinguistTools)
+message(STATUS "Using ${QT} with version ${QT_VERSION}")
+
+get_target_property(qmake_executable ${QT}::qmake IMPORTED_LOCATION)
+get_target_property(core_libdir ${QT}::Core IMPORTED_LOCATION)
+message(QTCORE ${core_libdir})
 get_filename_component(_qt_bin_dir "${qmake_executable}" DIRECTORY)
 find_program(MACDEPLOYQT_EXECUTABLE macdeployqt HINTS "${_qt_bin_dir}")
 find_program(WINDEPLOYQT_EXECUTABLE windeployqt HINTS "${_qt_bin_dir}")
@@ -93,9 +98,9 @@ endif()
 target_link_libraries(${CMAKE_PROJECT_NAME}
 	core widgets core
 	OpenSSL::Crypto
-	Qt5::Widgets Qt5::Core Qt5::Sql Qt5::Help
+	${QT}::Widgets ${QT}::Core ${QT}::Sql ${QT}::Help
 )
-target_link_libraries(xcadoc core Qt5::Core)
+target_link_libraries(xcadoc core ${QT}::Core)
 
 if (APPLE)
 
@@ -108,13 +113,13 @@ if (APPLE)
 
   ##### Plugins
 
-  get_target_property(sqlplugins Qt5::Sql QT_ALL_PLUGINS_sqldrivers)
+  get_target_property(sqlplugins ${QT}::Sql QT_ALL_PLUGINS_sqldrivers)
   message(STATUS "SQL Plugins ${sqlplugins}")
   foreach(sql ${sqlplugins})
     get_target_property(loc ${sql} LOCATION_${CMAKE_BUILD_TYPE})
     list(APPEND sqlplugin_paths "${loc}")
   endforeach()
-  qt5_import_plugins(${CMAKE_PROJECT_NAME} INCLUDE_BY_TYPE sqldrivers)
+  qt_import_plugins(${CMAKE_PROJECT_NAME} INCLUDE_BY_TYPE sqldrivers)
 
   # Avoid bin/ sub-directory in DMG
   set(RUNTIME_DEST .)
@@ -171,7 +176,7 @@ if(APPLE)
 	XCODE_ATTRIBUTE_SKIP_INSTALL No
 	RESOURCE "${APP_RESOURCES}"
   )
-  get_target_property(qmake_executable Qt5::qmake IMPORTED_LOCATION)
+  get_target_property(qmake_executable ${QT}::qmake IMPORTED_LOCATION)
   get_filename_component(_qt_bin_dir "${qmake_executable}" DIRECTORY)
   find_program(MACDEPLOYQT_EXECUTABLE macdeployqt HINTS ${_qt_bin_dir})
 
@@ -219,11 +224,11 @@ elseif(WIN32)
 	  ${CMAKE_BINARY_DIR}/styles
 	  DESTINATION ${RUNTIME_DEST}
   )
-  install(FILES ${CMAKE_BINARY_DIR}/Qt5Core.dll
-		${CMAKE_BINARY_DIR}/Qt5Gui.dll
-		${CMAKE_BINARY_DIR}/Qt5Help.dll
-		${CMAKE_BINARY_DIR}/Qt5Sql.dll
-		${CMAKE_BINARY_DIR}/Qt5Widgets.dll
+  install(FILES ${CMAKE_BINARY_DIR}/${QT}Core.dll
+		${CMAKE_BINARY_DIR}/${QT}Gui.dll
+		${CMAKE_BINARY_DIR}/${QT}Help.dll
+		${CMAKE_BINARY_DIR}/${QT}Sql.dll
+		${CMAKE_BINARY_DIR}/${QT}Widgets.dll
 		${CMAKE_BINARY_DIR}/libgcc_s_seh-1.dll
 		${CMAKE_BINARY_DIR}/libstdc++-6.dll
 		${CMAKE_BINARY_DIR}/libwinpthread-1.dll
diff --git a/cmake/git_version.cmake b/cmake/git_version.cmake
index d1f04741..c502a40b 100644
--- a/cmake/git_version.cmake
+++ b/cmake/git_version.cmake
@@ -48,5 +48,4 @@ if(Git_FOUND AND EXISTS "${PROJECT_SOURCE_DIR}/.git")
 
 endif()
 
-message(STATUS "VERSION: ${PROJECT_VERSION}")
-
+message(STATUS "XCA Version: ${PROJECT_VERSION}")
diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index e7c3f692..f9a1b483 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -129,7 +129,7 @@ if(SPHINX)
     endif()
 
   else(QTCOLLGEN)
-    message(WARNING "Neither 'qhelpgenerator' nor 'qcollectiongenerator' found. In-app documentation disabed. ${Qt5_DIR}/../../../bin")
+    message(WARNING "Neither 'qhelpgenerator' nor 'qcollectiongenerator' found. In-app documentation disabed. ${Qt_DIR}/../../../bin")
   endif(QTCOLLGEN)
 else(SPHINX)
   message(WARNING "sphinx-build binary not found. Documentation generation disabled")
diff --git a/lang/CMakeLists.txt b/lang/CMakeLists.txt
index 9ae75cf3..0d54a8c8 100644
--- a/lang/CMakeLists.txt
+++ b/lang/CMakeLists.txt
@@ -28,7 +28,11 @@ string(APPEND WIX_LANG_CONTENT
 
 WixFile(${D}/language.wxs ${WIX_LANG_CONTENT})
 
-qt5_add_translation(QM_FILES ${TS_FILES})
+if (${QT_VERSION} VERSION_LESS 6.0.0)
+  qt5_add_translation(QM_FILES ${TS_FILES})
+else()
+  qt_add_translation(QM_FILES ${TS_FILES})
+endif()
 list(APPEND APP_RESOURCES ${QM_FILES})
 
 add_custom_target(translations DEPENDS ${QM_FILES})
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index bd488d3d..2b635c69 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -1,10 +1,6 @@
-include_directories(${Qt5Sql_INCLUDE_DIRS}
-		${Qt5Core_INCLUDE_DIRS}
-		${Qt5Help_INCLUDE_DIRS}
-		${OPENSSL_INCLUDE_DIR}
-		${PROJECT_BINARY_DIR}
-		${PROJECT_SOURCE_DIR}
-)
+
+include_directories(${PROJECT_BINARY_DIR} ${PROJECT_SOURCE_DIR})
+
 add_library(core STATIC
 BioByteArray.cpp	dbhistory.cpp		pki_key.cpp
 BioByteArray.h		dbhistory.h		pki_key.h
@@ -42,3 +38,6 @@ XcaProgress.h		XcaWarningCore.cpp	XcaWarningCore.h
 PwDialogCore.cpp	PwDialogCore.h		digest.h
 digest.cpp		pki_export.cpp
 )
+
+target_link_libraries(core PRIVATE
+		OpenSSL::Crypto ${QT}::Core ${QT}::Sql ${QT}::Help)
diff --git a/lib/asn1time.cpp b/lib/asn1time.cpp
index f823e64f..53e2dfe8 100644
--- a/lib/asn1time.cpp
+++ b/lib/asn1time.cpp
@@ -26,7 +26,7 @@
 
 bool a1time::isUndefined() const
 {
-	return toTime_t() == 0;
+	return toSecsSinceEpoch() == 0;
 }
 
 a1time &a1time::setUndefined()
@@ -34,7 +34,7 @@ a1time &a1time::setUndefined()
 	/* This way we handle "Jan 01, 1970 00:00:00"
 	 * like RFC-5280 undefined date. I dare it */
 	setTimeSpec(Qt::UTC);
-	setTime_t(0);
+	setSecsSinceEpoch(0);
 	return *this;
 }
 
diff --git a/lib/db_base.cpp b/lib/db_base.cpp
index 52dfbe8d..227375a6 100644
--- a/lib/db_base.cpp
+++ b/lib/db_base.cpp
@@ -596,7 +596,12 @@ void db_base::timerEvent(QTimerEvent *event)
 				qDebug() << "Date changed for" << pki->getIntName() << ":" << hd->getName() << "Col:" << idx << t.toSortable();
 				QModelIndex i;
 				i = createIndex(rownumber(pki), idx, pki);
-				emit dataChanged(i, i);
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+				emit dataChanged(i, i, QList<int>{Qt::DisplayRole});
+#else
+				emit dataChanged(i, i, QVector<int>{Qt::DisplayRole});
+#endif
+
 			}
 		}
 	}
diff --git a/lib/func.cpp b/lib/func.cpp
index 184175ba..29d43bcf 100644
--- a/lib/func.cpp
+++ b/lib/func.cpp
@@ -237,7 +237,7 @@ const QString getDocDir()
 #ifdef DOCDIR
 	docs << QString(DOCDIR);
 #endif
-	docs += QStandardPaths::standardLocations(QStandardPaths::DataLocation);
+	docs += QStandardPaths::standardLocations(QStandardPaths::AppDataLocation);
 	foreach (docdir, docs) {
 #if !defined(Q_OS_MAC)
 		docdir += "/html";
@@ -275,7 +275,7 @@ const QString getUserSettingsDir()
 
 const QString getI18nDir()
 {
-	QString qm = QStandardPaths::locate(QStandardPaths::DataLocation,
+	QString qm = QStandardPaths::locate(QStandardPaths::AppDataLocation,
 		I18N_DIR "xca_de.qm");
 	return QFileInfo(qm).path();
 }
diff --git a/lib/pkcs11_lib.cpp b/lib/pkcs11_lib.cpp
index 27c1625a..f7d3b32a 100644
--- a/lib/pkcs11_lib.cpp
+++ b/lib/pkcs11_lib.cpp
@@ -14,7 +14,6 @@
 
 #include <openssl/rand.h>
 #include <QMessageBox>
-#include <QTextCodec>
 
 #include "ui_SelectToken.h"
 
diff --git a/lib/sql.cpp b/lib/sql.cpp
index 2732ced3..6afaadb4 100644
--- a/lib/sql.cpp
+++ b/lib/sql.cpp
@@ -150,7 +150,11 @@ QString XSqlQuery::rewriteQuery(QString _q)
 QString XSqlQuery::query_details()
 {
 	QString lq = lastq;
-	QList<QVariant> list = boundValues().values();
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+	QVariantList list = boundValues();
+#else
+	QVariantList list = boundValues().values();
+#endif
 	QStringList sl;
 
 	if (query != lastq) {
diff --git a/misc/dynamic.wxs.in b/misc/dynamic.wxs.in
index fded4b16..2edfd6db 100644
--- a/misc/dynamic.wxs.in
+++ b/misc/dynamic.wxs.in
@@ -13,6 +13,21 @@
 		Copy C:\Windows\System32\vcruntime140.dll C:\Windows\WOW64\
 		The WIX system uses that one and it crashes on the target.
 	    -->
+            <Component Id="CQtCore" Guid="561efd92-0fc8-4e2d-abe8-6ba16fc8bacd">
+                <File Id="QtCore.dll" Source="@QT@Core.dll" KeyPath="yes"/>
+            </Component>
+            <Component Id="CQtGui" Guid="2f680a70-2b2b-4b6e-9119-f53c8b5e1fe4">
+                <File Id="QtGui.dll" Source="@QT@Gui.dll" KeyPath="yes"/>
+            </Component>
+            <Component Id="CQtSql" Guid="df605486-2591-4232-8799-25ad2271e3d4">
+                <File Id="QtSql.dll" Source="@QT@Sql.dll" KeyPath="yes"/>
+            </Component>
+            <Component Id="CQtWidgets" Guid="eff9bc63-dc01-4f44-ab1f-8447a773817b">
+                <File Id="QtWidgets.dll" Source="@QT@Widgets.dll" KeyPath="yes"/>
+            </Component>
+            <Component Id="CQtHelp" Guid="83c15eef-0d1a-43a4-a0f7-1b90d0788705">
+                <File Id="QtHelp.dll" Source="@QT@Help.dll" KeyPath="yes"/>
+            </Component>
         </DirectoryRef>
         <FeatureGroup Id="DatabaseGroup">
             <Feature Id="Databases" Title="Database Drivers"
diff --git a/misc/xca.wxs b/misc/xca.wxs
index c3520096..f3330b2f 100644
--- a/misc/xca.wxs
+++ b/misc/xca.wxs
@@ -100,21 +100,6 @@
             <Component Id="Clibgcc_s_seh1" Guid="f5c27ddf-a2e1-49e2-9f24-fbf97bc5cb70">
                 <File Id="libgcc_s_seh1.dll" Source="libgcc_s_seh-1.dll" KeyPath="yes"/>
             </Component>
-            <Component Id="CQt5Core" Guid="561efd92-0fc8-4e2d-abe8-6ba16fc8bacd">
-                <File Id="Qt5Core.dll" Source="Qt5Core.dll" KeyPath="yes"/>
-            </Component>
-            <Component Id="CQt5Gui" Guid="2f680a70-2b2b-4b6e-9119-f53c8b5e1fe4">
-                <File Id="Qt5Gui.dll" Source="Qt5Gui.dll" KeyPath="yes"/>
-            </Component>
-            <Component Id="CQt5Sql" Guid="df605486-2591-4232-8799-25ad2271e3d4">
-                <File Id="Qt5Sql.dll" Source="Qt5Sql.dll" KeyPath="yes"/>
-            </Component>
-            <Component Id="CQt5Widgets" Guid="eff9bc63-dc01-4f44-ab1f-8447a773817b">
-                <File Id="Qt5Widgets.dll" Source="Qt5Widgets.dll" KeyPath="yes"/>
-            </Component>
-            <Component Id="CQt5Help" Guid="83c15eef-0d1a-43a4-a0f7-1b90d0788705">
-                <File Id="Qt5Help.dll" Source="Qt5Help.dll" KeyPath="yes"/>
-            </Component>
             <Component Id="Ccopyright.rtf" Guid="83c15eef-0d1a-43a4-a0f7-1b90d0784712">
                 <File Id="copyright.rtf" Source="$(var.CPACK_WIX_LICENSE_RTF)" KeyPath="yes"/>
             </Component>
@@ -188,11 +173,11 @@
             <ComponentRef Id="Clibgcc_s_seh1"/>
             <ComponentRef Id="Clibcrypto11x64"/>
             <ComponentRef Id="Cvcruntime140"/>
-            <ComponentRef Id="CQt5Core"/>
-            <ComponentRef Id="CQt5Gui"/>
-            <ComponentRef Id="CQt5Sql"/>
-            <ComponentRef Id="CQt5Widgets"/>
-            <ComponentRef Id="CQt5Help"/>
+            <ComponentRef Id="CQtCore"/>
+            <ComponentRef Id="CQtGui"/>
+            <ComponentRef Id="CQtSql"/>
+            <ComponentRef Id="CQtWidgets"/>
+            <ComponentRef Id="CQtHelp"/>
             <ComponentRef Id="Ccopyright.rtf"/>
             <ComponentRef Id="ApplicationShortcut" />
             <ComponentRef Id="RegistryEntries" />
@@ -201,7 +186,7 @@
         <Feature Id='Complete' Title='XCA' Description="Complete Installation"
                  Display='expand' Level='1' ConfigurableDirectory='INSTALLDIR'>
             <Feature Id="XCA" Title="Main Application" Level="1" Absent="disallow"
-                     Description="Contains the main application, required Qt5 libraries and the SQLite driver.">
+                     Description="Contains the main application, required Qt libraries and the SQLite driver.">
                 <ComponentGroupRef Id="GroupBasic" />
                 <ComponentGroupRef Id="GroupI18n" />
                 <ComponentGroupRef Id="GroupMisc" />
diff --git a/widgets/CMakeLists.txt b/widgets/CMakeLists.txt
index 1f36d414..599ebe1c 100644
--- a/widgets/CMakeLists.txt
+++ b/widgets/CMakeLists.txt
@@ -1,11 +1,6 @@
-include_directories(${Qt5Widgets_INCLUDE_DIRS}
-                ${Qt5Sql_INCLUDE_DIRS}
-                ${Qt5Core_INCLUDE_DIRS}
-                ${Qt5Help_INCLUDE_DIRS}
-                ${OPENSSL_INCLUDE_DIR}
-                ${PROJECT_BINARY_DIR}
-                ${PROJECT_SOURCE_DIR}
-)
+
+include_directories(${PROJECT_BINARY_DIR} ${PROJECT_SOURCE_DIR})
+
 add_library(widgets STATIC
 CertDetail.cpp		NewCrl.cpp		XcaApplication.h
 CertDetail.h		NewCrl.h		XcaDialog.cpp
@@ -34,3 +29,6 @@ MW_menu.cpp		X509SuperTreeView.cpp	v3ext.h
 MainWindow.cpp		X509SuperTreeView.h	validity.cpp
 MainWindow.h		XcaApplication.cpp	validity.h
 )
+
+target_link_libraries(widgets PRIVATE
+	OpenSSL::Crypto ${QT}::Widgets ${QT}::Core ${QT}::Sql ${QT}::Help)
diff --git a/widgets/CertDetail.cpp b/widgets/CertDetail.cpp
index 9e5cd1cc..dc4136dc 100644
--- a/widgets/CertDetail.cpp
+++ b/widgets/CertDetail.cpp
@@ -207,7 +207,7 @@ void CertDetail::setReq(pki_x509req *req)
 		QGridLayout *attrLayout = new QGridLayout(attributes);
 		attrLayout->setAlignment(Qt::AlignTop);
 		attrLayout->setSpacing(6);
-		attrLayout->setMargin(11);
+		attrLayout->setContentsMargins(11, 11, 11, 11);
 
 		for (int i = 0, ii = 0; i<cnt; i++) {
 			int nid;
diff --git a/widgets/Help.cpp b/widgets/Help.cpp
index c00cf3c5..f55626d2 100644
--- a/widgets/Help.cpp
+++ b/widgets/Help.cpp
@@ -12,6 +12,9 @@
 #include <QDialog>
 #include <QHelpEngine>
 #include <QDialogButtonBox>
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
+#include <QHelpLink>
+#endif
 
 Help::Help() : QWidget(NULL), helpengine(nullptr)
 {
@@ -42,19 +45,29 @@ void Help::content()
 	display(QUrl("qthelp://org.sphinx.xca/doc/index.html"));
 }
 
-QMap<QString, QUrl> Help::url_by_ctx(const QString &ctx) const
+QList<QUrl> Help::url_by_ctx(const QString &ctx) const
 {
 	if (!helpengine)
-		return QMap<QString, QUrl>();
-	return helpengine->linksForIdentifier(QString("%1.%1").arg(ctx));
+		return QList<QUrl>();
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
+	QList<QUrl> l;
+	foreach(QHelpLink hl,
+			helpengine->documentsForIdentifier(QString("%1.%1").arg(ctx)))
+	{
+		l << hl.url;
+	}
+	return l;
+#else
+	return helpengine->linksForIdentifier(QString("%1.%1").arg(ctx)).values();
+#endif
 }
 
 void Help::contexthelp(const QString &context)
 {
-	QMap<QString, QUrl> helpctx = url_by_ctx(context);
+	QList<QUrl> helpctx = url_by_ctx(context);
 
 	if (helpctx.count())
-		display(helpctx.constBegin().value());
+		display(helpctx.at(0));
 }
 
 void Help::contexthelp()
@@ -81,7 +94,7 @@ void Help::register_ctxhelp_button(QDialog *dlg, const QString &help_ctx) const
 	buttonBox->setProperty("help_ctx", QVariant(help_ctx));
 	connect(buttonBox, SIGNAL(helpRequested()), this, SLOT(contexthelp()));
 
-	if (helpengine && url_by_ctx(help_ctx).count() == 0) {
+	if (url_by_ctx(help_ctx).count() == 0) {
 		qWarning() << "Unknown help context: " << help_ctx;
 		buttonBox->button(QDialogButtonBox::Help)->setEnabled(false);
 	}
diff --git a/widgets/Help.h b/widgets/Help.h
index e99e93a3..82c9be37 100644
--- a/widgets/Help.h
+++ b/widgets/Help.h
@@ -26,7 +26,7 @@ class Help: public QWidget, public Ui::Help
 	~Help();
 	void register_ctxhelp_button(QDialog *dlg,
 					const QString &help_ctx) const;
-	QMap<QString, QUrl> url_by_ctx(const QString &ctx) const;
+	QList<QUrl> url_by_ctx(const QString &ctx) const;
 
    public slots:
 	void contexthelp();
diff --git a/widgets/KeyTreeView.cpp b/widgets/KeyTreeView.cpp
index 7ba7e5be..3865c287 100644
--- a/widgets/KeyTreeView.cpp
+++ b/widgets/KeyTreeView.cpp
@@ -14,6 +14,7 @@
 #include "ExportDialog.h"
 #include "XcaWarning.h"
 #include <QAbstractItemView>
+#include <QActionGroup>
 #include <QMenu>
 
 void KeyTreeView::fillContextMenu(QMenu *menu, QMenu *subExport,
diff --git a/widgets/MW_menu.cpp b/widgets/MW_menu.cpp
index ff1eac6b..13310cde 100644
--- a/widgets/MW_menu.cpp
+++ b/widgets/MW_menu.cpp
@@ -28,6 +28,7 @@
 #include <QMenuBar>
 #include <QMessageBox>
 #include <QFileDialog>
+#include <QActionGroup>
 
 static QAction *languageMenuEntry(const QStringList &sl)
 {
diff --git a/widgets/NewX509.cpp b/widgets/NewX509.cpp
index 23e7bb50..13cd8432 100644
--- a/widgets/NewX509.cpp
+++ b/widgets/NewX509.cpp
@@ -68,7 +68,8 @@ QList<nameEdit> NewX509::setupExplicitInputs(NIDlist nid_list,
 		layout = new QGridLayout(parent);
 		layout->setAlignment(Qt::AlignTop);
 		layout->setSpacing(6);
-		layout->setMargin(0);
+		layout->setContentsMargins(0, 0, 0, 0);
+		layout->setContentsMargins(11, 11, 11, 11);
 	}
 	int n = 0, col = 0;
 
diff --git a/widgets/Options.cpp b/widgets/Options.cpp
index 6317c0a5..2fdbe7fd 100644
--- a/widgets/Options.cpp
+++ b/widgets/Options.cpp
@@ -38,7 +38,8 @@ Options::Options(QWidget *parent)
 	  << tr("UTF8 strings only (RFC2459)")
 	  << tr("All strings");
 	mbstring->addItems(s);
-	mbstring->setCurrentIndex(string_opts.indexOf(Settings["string_opt"]));
+	mbstring->setCurrentIndex(string_opts.indexOf(
+								QString(Settings["string_opt"])));
 
 	searchP11 = NULL;
 	transDnEntries->setText(transDnEntries->text()
diff --git a/widgets/XcaApplication.cpp b/widgets/XcaApplication.cpp
index 2ae54fdb..caed957b 100644
--- a/widgets/XcaApplication.cpp
+++ b/widgets/XcaApplication.cpp
@@ -12,7 +12,6 @@
 #include "lib/entropy.h"
 
 #include <QClipboard>
-#include <QTextCodec>
 #include <QDir>
 #include <QFile>
 #include <QAction>
@@ -50,13 +49,13 @@ XcaApplication::XcaApplication(int &argc, char *argv[])
 	}
 
 	langAvail << QLocale::system();
-	langAvail << QString("en");
+	langAvail << QLocale("en");
 	QDirIterator qmIt(getI18nDir(), QStringList() << "*.qm", QDir::Files);
 	while (qmIt.hasNext()) {
 		XcaTranslator t;
 		qmIt.next();
 		QString language = qmIt.fileInfo().baseName().mid(4, -1);
-		if (t.load(language, "xca", getI18nDir()))
+		if (t.load(QLocale(language), "xca", getI18nDir()))
 			langAvail << QLocale(language);
 	}
 	setupLanguage(lang);
@@ -157,8 +156,13 @@ bool XcaApplication::eventFilter(QObject *watched, QEvent *ev)
 	case QEvent::NonClientAreaMouseMove:
 		if (mctr++ > 8) {
 			me = static_cast<QMouseEvent *>(ev);
-			Entropy::add(me->globalX());
-			Entropy::add(me->globalY());
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+			QPoint p = me->globalPosition().toPoint();
+#else
+			QPoint p = me->globalPos();
+#endif
+			Entropy::add(p.x());
+			Entropy::add(p.y());
 			mctr = 0;
 		}
 		break;
@@ -174,7 +178,7 @@ bool XcaApplication::eventFilter(QObject *watched, QEvent *ev)
 			dynamic_cast<XcaTreeView*>(watched->parent()) : NULL;
 
 		if ((watched == mainw || treeview) &&
-		    me->button() == Qt::MidButton &&
+		    me->button() == Qt::MiddleButton &&
 		    QApplication::clipboard()->supportsSelection())
 		{
 			mainw->pastePem();
diff --git a/widgets/distname.cpp b/widgets/distname.cpp
index 1db0ffbb..4bc3a648 100644
--- a/widgets/distname.cpp
+++ b/widgets/distname.cpp
@@ -23,16 +23,16 @@ DistName::DistName(QWidget* parent)
 	DistNameLayout = new QGridLayout();
 	DistNameLayout->setAlignment(Qt::AlignTop);
 	DistNameLayout->setSpacing(6);
-	DistNameLayout->setMargin(11);
+	DistNameLayout->setContentsMargins(11, 11, 11, 11);
 
 	QGridLayout *g = new QGridLayout();
 	g->setAlignment(Qt::AlignTop);
 	g->setSpacing(6);
-	g->setMargin(11);
+	g->setContentsMargins(11, 11, 11, 11);
 
 	QVBoxLayout *v = new QVBoxLayout(this);
 	v->setSpacing(6);
-	v->setMargin(11);
+	v->setContentsMargins(11, 11, 11, 11);
 	v->addLayout(DistNameLayout);
 	v->addStretch();
 	v->addLayout(g);