diff --git a/lib/libcasper/Makefile b/lib/libcasper/Makefile
index 3101f3378ff3..2f2d613bd1d9 100644
--- a/lib/libcasper/Makefile
+++ b/lib/libcasper/Makefile
@@ -1,5 +1,7 @@
 # $FreeBSD$
 
+.include <src.opts.mk>
+
 SUBDIR=		libcasper
 SUBDIR+=	services