diff --git a/CMakeLists.txt b/CMakeLists.txt
index ab165f0d1e..070c0e18d4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -526,7 +526,7 @@ endif()
 if(LYX_INSTALL_PREFIX)
 	set(CMAKE_INSTALL_PREFIX ${LYX_INSTALL_PREFIX} CACHE PATH "LyX user's choice install prefix" FORCE)
 	set(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
-        set(LYX_INSTALL_PREFIX ${LYX_INSTALL_PREFIX} CACHE PATH "LyX user's choice install prefix" FORCE)
+	set(LYX_INSTALL_PREFIX ${LYX_INSTALL_PREFIX} CACHE PATH "LyX user's choice install prefix" FORCE)
 endif()
 if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
          # see http://www.cmake.org/pipermail/cmake/2006-October/011559.html
@@ -788,6 +788,10 @@ set(QtCore5CompatLibrary)
 set(QtCore5CompatModule)
 if(LYX_USE_QT MATCHES "QT6|QT5")
 	if (LYX_USE_QT MATCHES "QT6")
+		if (CMAKE_CXX_STANDARD LESS 20)
+			message(STATUS "CXX_STANDARD = ${CMAKE_CXX_STANDARD}")
+			message(FATAL_ERROR "QT6 compilation requires at least CXX_STANDARD = 17")
+		endif()
 		set(QtVal "Qt6")
 		macro (qt_add_resources)
 			Qt6_add_resources(${ARGN})
@@ -796,6 +800,10 @@ if(LYX_USE_QT MATCHES "QT6|QT5")
 			Qt6_wrap_ui(${ARGN})
 		endmacro()
 	else()
+		if (CMAKE_CXX_STANDARD LESS 11)
+			message(STATUS "CXX_STANDARD = ${CMAKE_CXX_STANDARD}")
+			message(FATAL_ERROR "QT6 compilation requires at least CXX_STANDARD = 11")
+		endif()
 		set(QtVal "Qt5")
 		macro (qt_add_resources)
 			Qt5_add_resources(${ARGN})