diff -urNr boinc-client_release-7.14-7.14.2-orig/clientgui/AdvancedFrame.cpp boinc-client_release-7.14-7.14.2/clientgui/AdvancedFrame.cpp
--- boinc-client_release-7.14-7.14.2-orig/clientgui/AdvancedFrame.cpp	2018-10-11 02:43:27.000000000 +0200
+++ boinc-client_release-7.14-7.14.2/clientgui/AdvancedFrame.cpp	2019-03-06 17:10:57.196882227 +0100
@@ -347,11 +347,13 @@
         _("Select computer...\tCtrl+Shift+I"),
         _("Connect to a BOINC client on another computer")
     );
+#ifndef __WXGTK__
     menuFile->Append(
         ID_SHUTDOWNCORECLIENT, 
         _("Shut down connected client..."),
         _("Shut down the currently connected BOINC client")
     );
+#endif
     menuFile->AppendSeparator();
 
     strMenuDescription.Printf(