--- Makefile	(revision 486501)
+++ Makefile	(working copy)
@@ -23,7 +23,8 @@ 
 
 PORTSCOUT=	limitw:1,even
 
-USES=		gettext gnome localbase:ldflags meson pkgconfig python:3.6+,build tar:xz
+USES=		compiler:c11 gettext gnome localbase:ldflags meson pkgconfig \
+		python:3.6+,build tar:xz
 USE_GNOME=	gnomedesktop3 gtk30
 USE_XORG=	ice sm x11 xcomposite xtrans
 USE_GL=		egl gl glesv2