diff --git a/CMakeLists.txt b/CMakeLists.txt
index 04f3954350..0ceebc96a4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -512,6 +512,7 @@ endif()
 find_package(Qt5Core QUIET)
 if (Qt5Core_FOUND)
 	find_package(Qt5Widgets REQUIRED)
+        find_package(Qt5X11Extras)
 	set(QTVERSION ${Qt5Core_VERSION})
 	macro (qt_use_modules)
 		qt5_use_modules(${ARGN})
diff --git a/development/autotests/CMakeLists.txt b/development/autotests/CMakeLists.txt
index 9a6e6c4e8c..c1e19a4aff 100644
--- a/development/autotests/CMakeLists.txt
+++ b/development/autotests/CMakeLists.txt
@@ -8,7 +8,7 @@ set(LYX_HOME "out-home")
 set(LOCALE_DIR "${CMAKE_CURRENT_BINARY_DIR}/locale")
 file(MAKE_DIRECTORY "${LOCALE_DIR}" "${CMAKE_CURRENT_BINARY_DIR}/${LYX_HOME}")
 
-if(Q_WS_X11)
+if(QT_USES_X11)
   set(Missing)
   set(XVFBDLIBS)
   # Make sure, the needed programs are in PATH
diff --git a/development/cmake/ConfigureChecks.cmake b/development/cmake/ConfigureChecks.cmake
index 71291a53a5..035a62b0f6 100644
--- a/development/cmake/ConfigureChecks.cmake
+++ b/development/cmake/ConfigureChecks.cmake
@@ -112,3 +112,33 @@ check_cxx_source_compiles(
 	"
 SIZEOF_WCHAR_T_IS_4)
 
+if (Qt5X11Extras_FOUND)
+  get_target_property(_x11extra_prop Qt5::X11Extras IMPORTED_CONFIGURATIONS)
+  get_target_property(_x11extra_lib Qt5::X11Extras IMPORTED_SONAME_${_x11extra_prop})
+  set(CMAKE_REQUIRED_LIBRARIES ${_x11extra_lib})
+  set(CMAKE_REQUIRED_INCLUDES ${Qt5X11Extras_INCLUDE_DIRS})
+  set(CMAKE_REQUIRED_FLAGS ${Qt5X11Extras_EXECUTABLE_COMPILE_FLAGS})
+  check_cxx_source_compiles(
+          "
+          #include <QtX11Extras/QX11Info>
+          int main()
+          {
+            bool isX11 = QX11Info::isPlatformX11();
+          }
+          "
+  QT_USES_X11)
+elseif(QT4_FOUND)
+  set(CMAKE_REQUIRED_LIBRARIES ${QT_QTGUI_LIBRARY})
+  set(CMAKE_REQUIRED_INCLUDES ${QT_INCLUDES})
+  check_cxx_source_compiles(
+          "
+          #include <QtGui/QX11Info>
+          int main()
+          {
+            QX11Info *qxi = new QX11Info;
+            qxi->~QX11Info();
+          }
+          "
+  QT_USES_X11)
+endif()
+