diff --git a/math/clasp/Makefile b/math/clasp/Makefile
index 8cd62bc71138..f4c81c4e5775 100644
--- a/math/clasp/Makefile
+++ b/math/clasp/Makefile
@@ -1,28 +1,30 @@
 # Created by: Vsevolod Stakhov <vsevolod@FreeBSD.org>
 
 PORTNAME=	clasp
 PORTVERSION=	3.3.5
 DISTVERSIONPREFIX=	v
 CATEGORIES=	math devel
 
 MAINTAINER=	vsevolod@FreeBSD.org
 COMMENT=	Answer set solver for (extended) normal logic programs
 
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BROKEN_sparc64=	Fails to build: internal compiler error
 
 USES=	compiler:c++11-lang cmake
 
 USE_GITHUB=	yes
 GH_ACCOUNT=	potassco
 GH_PROJECT=	${PORTNAME}
 GH_TUPLE=	potassco:libpotassco:6e31cff:other/libpotassco
 
 PLIST_FILES=	bin/${PORTNAME}
 
+CONFLICTS_INSTALL=	clingo # bin/clasp is contained in clingo
+
 do-install:
 	${INSTALL_PROGRAM} ${INSTALL_WRKSRC}/bin/${PORTNAME} ${STAGEDIR}${PREFIX}/bin/${PORTNAME}
 
 .include <bsd.port.mk>
diff --git a/math/clingo/Makefile b/math/clingo/Makefile
index f0b0588e6e0b..c34236782af4 100644
--- a/math/clingo/Makefile
+++ b/math/clingo/Makefile
@@ -1,25 +1,32 @@
 PORTNAME=	clingo
 DISTVERSIONPREFIX=	v
-DISTVERSION=	5.4.1
+DISTVERSION=	5.5.0
 CATEGORIES=	math
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Grounder and solver for logic programs
 
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE.md
 
 BUILD_DEPENDS=	re2c:devel/re2c
 
 USES=		cmake compiler:c++14-lang
 USE_GITHUB=	yes
 GH_ACCOUNT=	potassco
-GH_TUPLE=	potassco:clasp:b089aa1509511ab403c0b9abd0d13eb9e873af44:potassco_clasp/clasp \
+GH_TUPLE=	potassco:clasp:a8dfc0a:potassco_clasp/clasp \
 		potassco:libpotassco:2f9fb7ca2c202f1b47643aa414054f2f4f9c1821:potassco_libpotassco/clasp/libpotassco
 
 USE_LDCONFIG=	yes
 
 CMAKE_OFF=	CLINGO_BUILD_WITH_PYTHON # broken, see https://github.com/potassco/clingo/issues/178
 CMAKE_OFF+=	CLINGO_BUILD_WITH_LUA
 
+CONFLICTS_INSTALL=	clasp # only installs bin/clasp that is included in clingo
+
+do-test:
+	${ECHO} "Testing ${PORTNAME}: solving 15puzzle"
+	@cd ${WRKSRC}/examples/clingo/15puzzle && \
+		${STAGEDIR}${PREFIX}/bin/clingo encoding.lp instance1.lp -c consecutive=0
+
 .include <bsd.port.mk>
diff --git a/math/clingo/distinfo b/math/clingo/distinfo
index 4f288d238b7a..9cef14bc2b2c 100644
--- a/math/clingo/distinfo
+++ b/math/clingo/distinfo
@@ -1,7 +1,7 @@
-TIMESTAMP = 1607489618
-SHA256 (potassco-clingo-v5.4.1_GH0.tar.gz) = ac6606388abfe2482167ce8fd4eb0737ef6abeeb35a9d3ac3016c6f715bfee02
-SIZE (potassco-clingo-v5.4.1_GH0.tar.gz) = 2822845
-SHA256 (potassco-clasp-b089aa1509511ab403c0b9abd0d13eb9e873af44_GH0.tar.gz) = ab2ac6601292619f94831065ee5c009f3168e14be52a65df7b9abdc20a1fc33f
-SIZE (potassco-clasp-b089aa1509511ab403c0b9abd0d13eb9e873af44_GH0.tar.gz) = 627136
+TIMESTAMP = 1619035809
+SHA256 (potassco-clingo-v5.5.0_GH0.tar.gz) = c9d7004a0caec61b636ad1c1960fbf339ef8fdee9719321fc1b6b210613a8499
+SIZE (potassco-clingo-v5.5.0_GH0.tar.gz) = 3027366
+SHA256 (potassco-clasp-a8dfc0a_GH0.tar.gz) = f96cf2baf9522e7a69a58cfe20f41aecf59b9509129e0ee4f6cb674ca89bd358
+SIZE (potassco-clasp-a8dfc0a_GH0.tar.gz) = 627911
 SHA256 (potassco-libpotassco-2f9fb7ca2c202f1b47643aa414054f2f4f9c1821_GH0.tar.gz) = 41eb8b7d87ecea48392de4ada455cda179cbd62fd63496355dea87e1e44b599f
 SIZE (potassco-libpotassco-2f9fb7ca2c202f1b47643aa414054f2f4f9c1821_GH0.tar.gz) = 210177
diff --git a/math/clingo/pkg-plist b/math/clingo/pkg-plist
index 6437ca208cb7..b3152fa2f1a3 100644
--- a/math/clingo/pkg-plist
+++ b/math/clingo/pkg-plist
@@ -1,14 +1,14 @@
 bin/clasp
 bin/clingo
 bin/gringo
 bin/lpconvert
 bin/reify
 include/clingo.h
 include/clingo.hh
 lib/cmake/Clingo/ClingoConfig.cmake
 lib/cmake/Clingo/ClingoConfigVersion.cmake
 lib/cmake/Clingo/ClingoTargets-%%CMAKE_BUILD_TYPE%%.cmake
 lib/cmake/Clingo/ClingoTargets.cmake
 lib/libclingo.so
-lib/libclingo.so.3
-lib/libclingo.so.3.0
+lib/libclingo.so.4
+lib/libclingo.so.4.0