diff --git a/config/qt4.m4 b/config/qt4.m4
index 2f5f775632..1cf557d637 100644
--- a/config/qt4.m4
+++ b/config/qt4.m4
@@ -179,11 +179,14 @@ AC_DEFUN([QT_DO_IT_ALL],
 	])
 
 	save_CPPFLAGS=$CPPFLAGS
-	AC_MSG_CHECKING([whether Qt uses the X Window system])
 	CPPFLAGS="$save_CPPFLAGS $QT_CORE_INCLUDES"
+	AC_CHECK_HEADER(QtGui/qtgui-config.h,
+	  [lyx_qt5_config=QtGui/qtgui-config.h],
+	  [lyx_qt5_config=qconfig.h],[-])
+	AC_MSG_CHECKING([whether Qt uses the X Window system])
 	if test x$USE_QT5 = xyes ; then
 	  AC_EGREP_CPP(xcb,
-	    [#include <qconfig.h>
+	    [#include <$lyx_qt5_config>
 	    QT_QPA_DEFAULT_PLATFORM_NAME],
 	    [AC_MSG_RESULT(yes)
 	     AC_DEFINE(QPA_XCB, 1, [Define if Qt uses the X Window System])],