diff --git a/devel/dconf/Makefile b/devel/dconf/Makefile
index 02ddfd76d18b..c4cd34dc8fc9 100644
--- a/devel/dconf/Makefile
+++ b/devel/dconf/Makefile
@@ -22,6 +22,7 @@ LIB_DEPENDS=	libdbus-1.so:devel/dbus
 PORTSCOUT=	limitw:1,even
 
 USES=		gettext gnome localbase meson pkgconfig python:3.6+,build tar:xz
+USE_CSTD=	c99
 USE_GNOME=	glib20 libxslt:build
 USE_LDCONFIG=	yes
 USE_BINUTILS=	yes