diff --git a/certi/Makefile b/certi/Makefile
index 6f1fdeec2ce46f0d253a725b456feb7a9f988c70..c52bc612329f4c1b91272949e6a0a6cdba7587e3 100644
--- a/certi/Makefile
+++ b/certi/Makefile
@@ -4,6 +4,7 @@
 
 COMMIT=		HEAD
 PKG_VERSION=	20130312
+PKGREVISION= 	1
 DISTNAME= 	certi-${PKG_VERSION}
 CATEGORIES=		architecture
 MASTER_SITES=	:pserver:anonymous@cvs.savannah.nongnu.org:/sources/certi@${COMMIT}+certi
@@ -14,6 +15,16 @@ HOMEPAGE=	https://savannah.nongnu.org/projects/certi
 COMMENT=	An Open Source HLA RTI (High Level Architecture)
 LICENSE=	gnu-gpl-v2
 
+PKG_SUPPORTED_OPTIONS+=		gui
+PKG_OPTION_DESCR.gui=		Enable GUI support
+define PKG_OPTION_SET.gui
+  CMAKE_ARGS+=			-DFORCE_NO_X11=OFF
+  include ../../mk/sysdep/libX11.mk
+endef
+define PKG_OPTION_UNSET.gui
+  CMAKE_ARGS+=			-DFORCE_NO_X11=ON
+endef
+
 include ../../mk/sysdep/cmake.mk
 include ../../mk/language/c.mk
 include ../../mk/language/c++.mk
diff --git a/certi/PLIST b/certi/PLIST
index 3988d05c3095e59e391fe6e5c9970f0bfd51add2..068d0cd1301fdcb628d87f2a324bfbc50794cb43 100644
--- a/certi/PLIST
+++ b/certi/PLIST
@@ -4,7 +4,7 @@ bin/CertiProcessus_A
 bin/CertiProcessus_B
 bin/MessageBufferTests
 bin/MsgBufferTests
-bin/billard
+${PLIST.gui}bin/billard
 bin/billard-nogui
 bin/hlaomtdif2cpp.py
 bin/rtia
@@ -77,7 +77,7 @@ lib/libRTI1516.so
 lib/libRTI1516.so.1
 lib/libRTI1516.so.1.0.0
 lib/libgraph-nogui.a
-lib/libgraph.a
+${PLIST.gui}lib/libgraph.a
 share/doc/certi/favicon.ico
 share/doc/certi/index.html
 share/federations/Test.fed