-Wparentheses warnings in GTK+ headers when compiling C++ code with GCC 8.1

Annoying since -Wparentheses is enabled when building with -Wall. Have to disable it to get rid of warnings/be able to build when building with -Werror. Example output when building with "-Wall -Werror":

In file included from /usr/include/gtk-3.0/gtk/gtk.h:100,
                 from ../src/ui/gtk/application_actions.h:25,
                 from ../src/ui/gtk/application_actions.cpp:20:
/usr/include/gtk-3.0/gtk/gtkfilechooserbutton.h:66:8: error: unnecessary parentheses in declaration of ‘__gtk_reserved1’ [-Werror=parentheses]
   void (*__gtk_reserved1);
        ^
/usr/include/gtk-3.0/gtk/gtkfilechooserbutton.h:67:8: error: unnecessary parentheses in declaration of ‘__gtk_reserved2’ [-Werror=parentheses]
   void (*__gtk_reserved2);
        ^
/usr/include/gtk-3.0/gtk/gtkfilechooserbutton.h:68:8: error: unnecessary parentheses in declaration of ‘__gtk_reserved3’ [-Werror=parentheses]
   void (*__gtk_reserved3);
        ^
/usr/include/gtk-3.0/gtk/gtkfilechooserbutton.h:69:8: error: unnecessary parentheses in declaration of ‘__gtk_reserved4’ [-Werror=parentheses]
   void (*__gtk_reserved4);