diff --git a/devel/tl-expected/Makefile b/devel/tl-expected/Makefile
new file mode 100644
index 00000000000..4ade0599651
--- /dev/null
+++ b/devel/tl-expected/Makefile
@@ -0,0 +1,45 @@
+# $OpenBSD: Makefile,v 1.1.1.1 2021/12/17 17:17:32 kn Exp $
+
+COMMENT =	c++11/14/17 std::expected with functional-style extensions
+
+GH_ACCOUNT =		TartanLlama
+GH_PROJECT =		expected
+GH_TAGNAME =		v1.0.0
+PKGNAME =		tl-${DISTNAME}
+CATEGORIES =		devel
+
+# cmake file for build and install;  no release or tags, use latest master
+ADD_TL_COMMIT =		284c6a3f0f61823cc3871b0f193e8df699e2c4ce
+MASTER_SITES0 =	https://raw.githubusercontent.com/${GH_ACCOUNT}/tl-cmake/${ADD_TL_COMMIT}/
+DISTFILES =		${GH_DISTFILE} \
+			add-tl.cmake:0
+EXTRACT_ONLY =		${GH_DISTFILE}
+
+HOMEPAGE =		https://tl.tartanllama.xyz
+
+# CC0 1.0 Universal (public domain)
+PERMIT_PACKAGE =	Yes
+
+MAINTAINER =		Klemens Nanni <kn@openbsd.org>
+
+# C++11 or higher
+COMPILER =		base-clang ports-gcc
+COMPILER_LANGS =	c++
+
+MODULES =		devel/cmake
+
+# avoid network and point at prefetched SUPDISTFILES
+CONFIGURE_ARGS +=	-DFETCHCONTENT_FULLY_DISCONNECTED=ON \
+			-DFETCHCONTENT_SOURCE_DIR_TL_CMAKE=${FULLDISTDIR}
+
+# avoid building anything for now, enable later
+CONFIGURE_ARGS +=	-DEXPECTED_ENABLE_TESTS=OFF
+
+# just header files
+PKG_ARCH =		*
+# with tests disabled and no docs or examples:
+# "ninja: no work to do."
+NO_BUILD =		Yes
+NO_TEST =		Yes
+
+.include <bsd.port.mk>
diff --git a/devel/tl-expected/distinfo b/devel/tl-expected/distinfo
new file mode 100644
index 00000000000..582ade356fe
--- /dev/null
+++ b/devel/tl-expected/distinfo
@@ -0,0 +1,4 @@
+SHA256 (add-tl.cmake) = 5wh8w31CXmUx53/Q8pbOpr21AOVFH+aSvS8FsAN+SGY=
+SHA256 (expected-1.0.0.tar.gz) = j1EkCFoSQRPnXjiQtOkj46TeWyapc7iRs960DhnAPO4=
+SIZE (add-tl.cmake) = 1366
+SIZE (expected-1.0.0.tar.gz) = 102672
diff --git a/devel/tl-expected/pkg/DESCR b/devel/tl-expected/pkg/DESCR
new file mode 100644
index 00000000000..5b4b63c621e
--- /dev/null
+++ b/devel/tl-expected/pkg/DESCR
@@ -0,0 +1,9 @@
+tl-expected is a single header implementation of `std::expected` with
+functional-style extensions.
+
+std::expected is proposed as the preferred way to represent an object which
+will either have an expected value, or an unexpected value giving
+information about why something failed.  Unfortunately, chaining together
+many computations which may fail can be verbose, as error-checking code will
+be mixed in with the actual programming logic.  This implementation provides
+a number of utilities to make coding with expected cleaner.
diff --git a/devel/tl-expected/pkg/PLIST b/devel/tl-expected/pkg/PLIST
new file mode 100644
index 00000000000..7372cf42f6f
--- /dev/null
+++ b/devel/tl-expected/pkg/PLIST
@@ -0,0 +1,8 @@
+@comment $OpenBSD: PLIST,v 1.1.1.1 2021/12/17 17:17:32 kn Exp $
+include/tl/
+include/tl/expected.hpp
+share/cmake/
+share/cmake/tl-expected/
+share/cmake/tl-expected/tl-expected-config-version.cmake
+share/cmake/tl-expected/tl-expected-config.cmake
+share/cmake/tl-expected/tl-expected-targets.cmake