diff --git a/kBuild/units/qt5.kmk b/kBuild/units/qt5.kmk
index 71b96a3..73391f0 100644
--- a/kBuild/units/qt5.kmk
+++ b/kBuild/units/qt5.kmk
@@ -1019,9 +1019,10 @@ else
    $(eval $(target)_LIBS   += $(PATH_SDK_QT5_LIB)/$(qt_prefix)qtmain$(qt_infix)$(SUFF_LIB) )
   endif
  else
-  $(eval $(target)_LIBS    += $(foreach module,$(qt_modules), $(PATH_SDK_QT5_LIB)/lib$(qt_prefix)Qt5$(module)$(qt_infix)$(SUFF_DLL)) )
+  $(eval $(target)_LIBS    += $(foreach module,$(qt_modules), $(PATH_SDK_QT5_LIB)/lib$(qt_prefix)Qt5$(module)$(qt_infix)$(SUFF_DLL)) \
+                              $(PATH_QT5_X11_EXTRAS_LIB)/lib$(qt_prefix)Qt5X11Extras$(qt_infix)$(SUFF_DLL))
  endif
- $(eval $(target)_INCS     += $(addprefix $(PATH_SDK_QT5_INC)/Qt,$(qt_modules)) $(PATH_SDK_QT5_INC) )
+ $(eval $(target)_INCS     += $(addprefix $(PATH_SDK_QT5_INC)/Qt,$(qt_modules)) $(PATH_SDK_QT5_INC) $(PATH_QT5_X11_EXTRAS_INC)/QtX11Extras )
 endif
 $(eval $(target)_DEFS      += $(foreach module,$(toupper $(qt_modules)), QT_$(module)_LIB) )

diff --git a/src/VBox/Frontends/VirtualBox/Makefile.kmk b/src/VBox/Frontends/VirtualBox/Makefile.kmk
index 3295bfefe7..796370623c 100644
--- a/src/VBox/Frontends/VirtualBox/Makefile.kmk
+++ b/src/VBox/Frontends/VirtualBox/Makefile.kmk
@@ -916,9 +916,6 @@ endif
 # The Qt modules we're using.
 # (The include directory and lib/framework for each module will be added by the Qt unit.)
 VirtualBox_QT_MODULES = Core Gui Widgets PrintSupport
-VirtualBox_QT_MODULES.linux   += X11Extras
-VirtualBox_QT_MODULES.solaris += X11Extras
-VirtualBox_QT_MODULES.freebsd += X11Extras
 VirtualBox_QT_MODULES.darwin  += MacExtras
 VirtualBox_QT_MODULES.win     += WinExtras
 if defined(VBOX_WITH_VIDEOHWACCEL) || defined(VBOX_GUI_USE_QGL)