diff --git a/cad/horizon-eda/Makefile b/cad/horizon-eda/Makefile
index 1da05dafc3f7..4e9f0c71ef51 100644
--- a/cad/horizon-eda/Makefile
+++ b/cad/horizon-eda/Makefile
@@ -1,45 +1,49 @@
 PORTNAME=	horizon-eda
 DISTVERSIONPREFIX=	v
 DISTVERSION=	2.1.0
 PORTREVISION=	1
 CATEGORIES=	cad
 
+PATCH_SITES=	https://github.com/${GH_ACCOUNT}/${GH_PROJECT}/commit/
+PATCHFILES=	0d801d4807cbed405998688b361bf0543207f1b1.patch:-p1 # fixes opencascade-7.6.0 compatibility, see https://github.com/horizon-eda/horizon/issues/623
+
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	EDA package for printed circuit board design
 
 LICENSE=	GPLv3
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BUILD_DEPENDS=	${LOCALBASE}/include/boost/optional.hpp:devel/boost-libs \
 		cppzmq>0:net/cppzmq \
 		glm>0:math/glm
 LIB_DEPENDS=	libcurl.so:ftp/curl \
 		libepoxy.so:graphics/libepoxy \
 		libgit2.so:devel/libgit2 \
 		libharfbuzz.so:print/harfbuzz \
 		libpng16.so:graphics/png \
 		libpodofo.so:graphics/podofo \
 		libTKSTEP.so:cad/opencascade \
 		libuuid.so:misc/e2fsprogs-libuuid \
 		libzip.so:archivers/libzip \
 		libzmq.so:net/libzmq4
 
 USES=		gmake gnome localbase pkgconfig python:build sqlite # compiler:c++17-lang
+USE_GNOME=	atkmm gdkpixbuf2 gtkmm30 librsvg2
+
 USE_GITHUB=	yes
 GH_PROJECT=	horizon
-USE_GNOME=	atkmm gdkpixbuf2 gtkmm30 librsvg2
 
 MAKE_ARGS=	DEBUGFLAGS= OPTIMIZE=
 
 BINARY_ALIAS=	python3=${PYTHON_CMD}
 
-LLVM_VER=	10 # workaround for bug#253551
+LLVM_VER=	12 # workaround for bug#253551
 BUILD_DEPENDS+=	clang${LLVM_VER}:devel/llvm${LLVM_VER}
 CPP=		clang-cpp${LLVM_VER}
 CC=		clang${LLVM_VER}
 CXX=		clang++${LLVM_VER}
 
 post-install: # https://github.com/horizon-eda/horizon/issues/558
 	cd ${STAGEDIR}${PREFIX}/bin && ${STRIP_CMD} horizon-eda
 
 .include <bsd.port.mk>
diff --git a/cad/horizon-eda/distinfo b/cad/horizon-eda/distinfo
index cd99d6795f21..e978eeef3a49 100644
--- a/cad/horizon-eda/distinfo
+++ b/cad/horizon-eda/distinfo
@@ -1,3 +1,5 @@
-TIMESTAMP = 1631174790
+TIMESTAMP = 1637022213
 SHA256 (horizon-eda-horizon-v2.1.0_GH0.tar.gz) = 2ba7a64ef0d8f22ad12e6a5a9c108f865eeb468f954f51ee5fbc03e6a847549a
 SIZE (horizon-eda-horizon-v2.1.0_GH0.tar.gz) = 3140793
+SHA256 (0d801d4807cbed405998688b361bf0543207f1b1.patch) = 64c0200aaf39e967d26d41634fea17db32f779449cd0a05197446e1a973b4d1f
+SIZE (0d801d4807cbed405998688b361bf0543207f1b1.patch) = 2501