diff --git a/CMakeLists.txt b/CMakeLists.txt
index f8ca0c10fd..12dd3947be 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -219,7 +219,7 @@ else()
 endif()
 LYX_OPTION(ASAN             "Use address sanitizer" OFF ALL)
 #LYX_COMBO(USE_FILEDIALOG    "Use native or QT file dialog" QT NATIVE)
-LYX_COMBO(USE_QT            "Use Qt version as frontend" AUTO QT4 QT5)
+LYX_COMBO(USE_QT            "Use Qt version as frontend" AUTO QT4 QT5 QT6)
 LYX_COMBO(USE_IPO           "Interprocedural optimization" OFF AUTO ON)
 #LYX_OPTION(3RDPARTY_BUILD   "Build 3rdparty libs" OFF ALL)
 LYX_OPTION(DISABLE_CALLSTACK_PRINTING "do not print a callstack when crashing" OFF ALL)
@@ -743,32 +743,58 @@ endif()
 
 set(min_qt5_version "5.6")
 if(LYX_USE_QT MATCHES "AUTO")
-	# try qt5 first
-	find_package(Qt5Core CONFIG QUIET)
-	if(Qt5Core_FOUND)
-		set(LYX_USE_QT "QT5" CACHE STRING "Valid qt version" FORCE)
+	# try qt6 first
+	find_package(Qt6Core CONFIG QUIET)
+	if (Qt6Core_Found)
+		set(LYX_USE_QT "QT6" CACHE STRING "Valid qt version" FORCE)
 		message(STATUS "Qt5Core_VERSION = ${Qt5Core_VERSION}")
-		if(Qt5Core_VERSION VERSION_LESS ${min_qt5_version})
-			find_package(Qt4 "4.5.0" QUIET)
-			if(QT4_FOUND)
-				set(LYX_USE_QT "QT4" CACHE STRING "Valid qt version" FORCE)
-			endif()
-		endif()
 	else()
-		set(LYX_USE_QT "QT4" CACHE STRING "Valid qt version" FORCE)
+		find_package(Qt5Core CONFIG QUIET)
+		if(Qt5Core_FOUND)
+			set(LYX_USE_QT "QT5" CACHE STRING "Valid qt version" FORCE)
+			message(STATUS "Qt5Core_VERSION = ${Qt5Core_VERSION}")
+			if(Qt5Core_VERSION VERSION_LESS ${min_qt5_version})
+				find_package(Qt4 "4.5.0" QUIET)
+				if(QT4_FOUND)
+					set(LYX_USE_QT "QT4" CACHE STRING "Valid qt version" FORCE)
+				endif()
+			endif()
+		else()
+			set(LYX_USE_QT "QT4" CACHE STRING "Valid qt version" FORCE)
+		endif()
 	endif()
 endif()
-if(LYX_USE_QT MATCHES "QT5")
+
+set(QtCore5CompatLibrary)
+set(QtCore5CompatModule)
+if(LYX_USE_QT MATCHES "QT6|QT5")
+	if (LYX_USE_QT MATCHES "QT6")
+		set(QtVal "Qt6")
+		macro (qt_add_resources)
+			Qt6_add_resources(${ARGN})
+		endmacro()
+		macro (qt_wrap_uifiles)
+			Qt6_wrap_ui(${ARGN})
+		endmacro()
+	else()
+		set(QtVal "Qt5")
+		macro (qt_add_resources)
+			Qt5_add_resources(${ARGN})
+		endmacro()
+		macro (qt_wrap_uifiles)
+			Qt5_wrap_ui(${ARGN})
+		endmacro()
+	endif()
 	# set QPA_XCB if QT uses X11
-	find_package(Qt5Core CONFIG REQUIRED)
-	if (Qt5Core_FOUND)
-		find_package(Qt5Widgets CONFIG REQUIRED)
+	find_package(${QtVal}Core CONFIG REQUIRED)
+	if (${QtVal}Core_FOUND)
+		find_package(${QtVal}Widgets CONFIG REQUIRED)
 		if(APPLE)
-			find_package(Qt5MacExtras CONFIG REQUIRED)
+			find_package(${QtVal}MacExtras CONFIG REQUIRED)
 		endif()
-		find_package(Qt5X11Extras CONFIG QUIET)
-		find_package(Qt5WinExtras CONFIG QUIET)
-		set(QTVERSION ${Qt5Core_VERSION})
+		find_package(${QtVal}X11Extras CONFIG QUIET)
+		find_package(${QtVal}WinExtras CONFIG QUIET)
+		set(QTVERSION ${${QtVal}Core_VERSION})
 		if (QTVERSION VERSION_LESS ${min_qt5_version})
 			message(STATUS "QTVERSION = \"${QTVERSION}\"")
 			message(STATUS "This version is not recommended, try either option -DLYX_USE_QT=QT4 or")
@@ -781,19 +807,20 @@ if(LYX_USE_QT MATCHES "QT5")
 		endif()
 		macro (qt_use_modules lyxtarget)
 			foreach (_tg ${ARGN})
-				find_package(Qt5${_tg} CONFIG REQUIRED)
-				target_link_libraries(${lyxtarget} Qt5::${_tg})
+				find_package(${QtVal}${_tg} CONFIG REQUIRED)
+				target_link_libraries(${lyxtarget} ${QtVal}::${_tg})
 			endforeach()
 		endmacro()
-		macro (qt_add_resources)
-			qt5_add_resources(${ARGN})
-		endmacro()
-		macro (qt_wrap_uifiles)
-			qt5_wrap_ui(${ARGN})
-		endmacro()
 		message(STATUS "Found Qt-Version ${QTVERSION}")
 		if(WIN32)
-			set(LYX_QTMAIN_LIBRARY ${Qt5Core_QTMAIN_LIBRARIES})
+			set(LYX_QTMAIN_LIBRARY ${${QtVal}Core_QTMAIN_LIBRARIES})
+		endif()
+		if (LYX_USE_QT MATCHES "QT6")
+			get_target_property(QT_MOC_EXECUTABLE Qt6::moc LOCATION)
+			find_package(Qt6 COMPONENTS Core5Compat REQUIRED)
+			include_directories(${Qt6Core5Compat_INCLUDE_DIRS})
+			set(QtCore5CompatLibrary Qt6::Core5Compat)
+			set(QtCore5CompatModule Core5Compat)
 		endif()
 	endif()
 elseif(LYX_USE_QT MATCHES "QT4")
diff --git a/development/cmake/ConfigureChecks.cmake b/development/cmake/ConfigureChecks.cmake
index 616bec0a10..29ad935c65 100644
--- a/development/cmake/ConfigureChecks.cmake
+++ b/development/cmake/ConfigureChecks.cmake
@@ -277,11 +277,16 @@ endif()
 
 set(QPA_XCB)
 set(HAVE_QT5_X11_EXTRAS)
-if(LYX_USE_QT MATCHES "QT5")
-
+set(HAVE_QT6_X11_EXTRAS)
+if (LYX_USE_QT MATCHES "QT5|QT6")
+  if (LYX_USE_QT MATCHES "QT5")
+    set(QtVal Qt5)
+  else()
+    set(QtVal Qt6)
+  endif()
   set(CMAKE_REQUIRED_INCLUDES ${Qt5Core_INCLUDE_DIRS})
   set(CMAKE_REQUIRED_FLAGS)
-  #message(STATUS "Qt5Core_INCLUDE_DIRS = ${Qt5Core_INCLUDE_DIRS}")
+  #message(STATUS "${QtVal}Core_INCLUDE_DIRS = ${${QtVal}Core_INCLUDE_DIRS}")
   check_include_file_cxx(QtGui/qtgui-config.h HAVE_QTGUI_CONFIG_H)
   if (HAVE_QTGUI_CONFIG_H)
     set(lyx_qt5_config "QtGui/qtgui-config.h")
@@ -312,14 +317,14 @@ if(LYX_USE_QT MATCHES "QT5")
     endif()
   endif()
 
-  if (Qt5X11Extras_FOUND)
-    get_target_property(_x11extra_prop Qt5::X11Extras IMPORTED_CONFIGURATIONS)
-    get_target_property(_x11extra_link_libraries Qt5::X11Extras IMPORTED_LOCATION_${_x11extra_prop})
+  if (${QtVal}X11Extras_FOUND)
+    get_target_property(_x11extra_prop ${QtVal}::X11Extras IMPORTED_CONFIGURATIONS)
+    get_target_property(_x11extra_link_libraries ${QtVal}::X11Extras IMPORTED_LOCATION_${_x11extra_prop})
     set(CMAKE_REQUIRED_LIBRARIES ${_x11extra_link_libraries})
-    set(CMAKE_REQUIRED_INCLUDES ${Qt5X11Extras_INCLUDE_DIRS})
-    set(CMAKE_REQUIRED_FLAGS "${Qt5X11Extras_EXECUTABLE_COMPILE_FLAGS} -fPIC -DQT_NO_VERSION_TAGGING")
+    set(CMAKE_REQUIRED_INCLUDES ${${QtVal}X11Extras_INCLUDE_DIRS})
+    set(CMAKE_REQUIRED_FLAGS "${${QtVal}X11Extras_EXECUTABLE_COMPILE_FLAGS} -fPIC -DQT_NO_VERSION_TAGGING")
     #message(STATUS "CMAKE_REQUIRED_LIBRARIES = ${_x11extra_link_libraries}")
-    #message(STATUS "CMAKE_REQUIRED_INCLUDES = ${Qt5X11Extras_INCLUDE_DIRS}")
+    #message(STATUS "CMAKE_REQUIRED_INCLUDES = ${${QtVal}X11Extras_INCLUDE_DIRS}")
     #message(STATUS "CMAKE_REQUIRED_FLAGS = ${CMAKE_REQUIRED_FLAGS}")
     check_cxx_source_compiles(
             "
@@ -333,13 +338,13 @@ if(LYX_USE_QT MATCHES "QT5")
     set(HAVE_QT5_X11_EXTRAS ${QT_HAS_X11_EXTRAS})
     set(LYX_QT5_X11_EXTRAS_LIBRARY ${_x11extra_link_libraries})
   endif()
-  if (Qt5WinExtras_FOUND)
-    get_target_property(_winextra_prop Qt5::WinExtras IMPORTED_CONFIGURATIONS)
+  if (${QtVal}WinExtras_FOUND)
+    get_target_property(_winextra_prop ${QtVal}::WinExtras IMPORTED_CONFIGURATIONS)
     string(TOUPPER ${CMAKE_BUILD_TYPE} BUILD_TYPE)
-    get_target_property(_winextra_link_libraries Qt5::WinExtras IMPORTED_LOCATION_${BUILD_TYPE})
+    get_target_property(_winextra_link_libraries ${QtVal}::WinExtras IMPORTED_LOCATION_${BUILD_TYPE})
     set(CMAKE_REQUIRED_LIBRARIES ${_winextra_link_libraries})
-    set(CMAKE_REQUIRED_INCLUDES ${Qt5WinExtras_INCLUDE_DIRS})
-    set(CMAKE_REQUIRED_FLAGS ${Qt5WinExtras_EXECUTABLE_COMPILE_FLAGS})
+    set(CMAKE_REQUIRED_INCLUDES ${${QtVal}WinExtras_INCLUDE_DIRS})
+    set(CMAKE_REQUIRED_FLAGS ${${QtVal}WinExtras_EXECUTABLE_COMPILE_FLAGS})
   endif()
 elseif(LYX_USE_QT MATCHES "QT4")
   set(CMAKE_REQUIRED_LIBRARIES ${QT_QTGUI_LIBRARY})
diff --git a/development/cmake/LyxPackaging.cmake b/development/cmake/LyxPackaging.cmake
index cfd1c5c8e2..6d308d06d9 100644
--- a/development/cmake/LyxPackaging.cmake
+++ b/development/cmake/LyxPackaging.cmake
@@ -154,7 +154,7 @@ set(CPACK_SOURCE_PACKAGE_FILE_NAME "${LYX_PROJECT}-${LYX_INSTALL_SUFFIX}")
 # Currently no need to specify versions for pythonx since they are only
 # available in newest distributions.
 set(CPACK_DEBIAN_PACKAGE_DEPENDS "python (>= 2.7) | python3 | python2")
-set(CPACK_DEBIAN_PACKAGE_SECTION "editors")
+set(CPACK_DEBIAN_PACKAGE_SECTION "universe/editors")
 
 # use dpkg-shlibdeps to generate additional info for package dependency list.
 set(CPACK_DEBIAN_PACKAGE_RELEASE ${LYX_PACKAGE_RELEASE})
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4fbe440a34..84373dac33 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -141,7 +141,8 @@ target_link_libraries(${_lyx}
 	${LYX_QTMAIN_LIBRARY}
 	${vld_dll})
 
-qt_use_modules(${_lyx} Core Gui)
+qt_use_modules(${_lyx} Core Gui ${QtCore5CompatModule})
+target_link_libraries(${_lyx} ${QtCore5CompatLibrary})
 
 if(QT_USES_X11)
   find_package(X11 REQUIRED)
diff --git a/src/client/CMakeLists.txt b/src/client/CMakeLists.txt
index 95535e0a61..c64ada8ef4 100644
--- a/src/client/CMakeLists.txt
+++ b/src/client/CMakeLists.txt
@@ -26,8 +26,10 @@ target_link_libraries(${_lyxclient}
 	${Lyx_Boost_Libraries}
 	${ICONV_LIBRARY}
 	${QT_QTCORE_LIBRARY}
-	${QT_QTGUI_LIBRARY})
+	${QT_QTGUI_LIBRARY}
+	${QtCore5CompatLibrary})
 
+qt_use_modules(${_lyxclient} ${QtCore5CompatModule})
 lyx_target_link_libraries(${_lyxclient} Magic ASPELL)
 
 if(APPLE)
diff --git a/src/support/tests/CMakeLists.txt b/src/support/tests/CMakeLists.txt
index e5ef4fa6a8..4667077f71 100644
--- a/src/support/tests/CMakeLists.txt
+++ b/src/support/tests/CMakeLists.txt
@@ -14,13 +14,14 @@ macro(sources _program)
 	set(${_program}_SOURCES ${_tmplist})
 	add_executable(${_program} ${_tmplist})
 	target_link_libraries(${_program} support
-		${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY}
+		${Lyx_Boost_Libraries}
+		${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY} ${QtCore5CompatLibrary}
 		${ZLIB_LIBRARY} ${ICONV_LIBRARY})
 	lyx_target_link_libraries(${_program} Magic)
 	if(CYGWIN)
 		target_link_libraries(${_program} shlwapi)
 	endif()
-	qt_use_modules(${_program} Core)
+	qt_use_modules(${_program} Core ${QtCore5CompatModule})
 	set_property(TARGET ${_program} PROPERTY INTERPROCEDURAL_OPTIMIZATION FALSE)
 endmacro()
 
diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index 957e4c0cd7..0fe014f9c2 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -17,7 +17,7 @@ include_directories(${TOP_SRC_DIR}/src/support/tests)
 add_executable(check_layout ${check_layout_SOURCES})
 
 target_link_libraries(check_layout support
-  ${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY}
+  ${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY} ${QtCore5CompatLibrary}
   ${ZLIB_LIBRARY} ${ICONV_LIBRARY})
 if(CYGWIN)
     target_link_libraries(check_layout shlwapi)
@@ -75,7 +75,7 @@ include_directories(${TOP_SRC_DIR}/src/tests)
 add_executable(check_ExternalTransforms ${check_ExternalTransforms_SOURCES})
 
 target_link_libraries(check_ExternalTransforms support
-	${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY})
+	${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY} ${QtCore5CompatLibrary})
 lyx_target_link_libraries(check_ExternalTransforms Magic)
 
 add_dependencies(lyx_run_tests check_ExternalTransforms)
@@ -96,7 +96,7 @@ endforeach()
 add_executable(check_Length ${check_Length_SOURCES})
 
 target_link_libraries(check_Length support
-	${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY})
+	${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY} ${QtCore5CompatLibrary})
 lyx_target_link_libraries(check_Length Magic)
 
 add_dependencies(lyx_run_tests check_Length)
@@ -118,7 +118,7 @@ endforeach()
 add_executable(check_ListingsCaption ${check_ListingsCaption_SOURCES})
 
 target_link_libraries(check_ListingsCaption support
-	${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY})
+	${Lyx_Boost_Libraries} ${QT_QTGUI_LIBRARY} ${QT_QTCORE_LIBRARY} ${QtCore5CompatLibrary})
 lyx_target_link_libraries(check_ListingsCaption Magic)
 
 add_dependencies(lyx_run_tests check_ListingsCaption)
diff --git a/src/tex2lyx/CMakeLists.txt b/src/tex2lyx/CMakeLists.txt
index 2a68e71150..f3bfc52603 100644
--- a/src/tex2lyx/CMakeLists.txt
+++ b/src/tex2lyx/CMakeLists.txt
@@ -48,8 +48,10 @@ target_link_libraries(${_tex2lyx}
 	${Lyx_Boost_Libraries}
 	${QT_QTCORE_LIBRARY}
 	${QT_QTGUI_LIBRARY}
+	${QtCore5CompatLibrary}
 	${ICONV_LIBRARY})
 
+qt_use_modules(${_tex2lyx} ${QtCore5CompatModule})
 lyx_target_link_libraries(${_tex2lyx} Magic)
 
 add_dependencies(${_tex2lyx} lyx_version)