diff --git a/media-gfx/opencsg/Manifest b/media-gfx/opencsg/Manifest
index a51db6d1b7f9b..5cab50fa180ef 100644
--- a/media-gfx/opencsg/Manifest
+++ b/media-gfx/opencsg/Manifest
@@ -1 +1,2 @@
 DIST OpenCSG-1.6.0.tar.gz 302547 BLAKE2B ceb99fb6558b38df0eb629cfd5e5e2b768311f026f2f42e0e35ca948761bd7c67fcfc35322d54eb6c013eded39d95ede08f634b30241ebad4231bf783f76b591 SHA512 0cbf28353aafb47738a122bd5fa8e8ab0abc616d7b3f4e5f1ee02f550a060ccfbd6569d1183fcc4e992fe9bbb49584c23aa9cc7db2a7e7c53b119544aa9589a7
+DIST OpenCSG-1.8.1.tar.gz 305467 BLAKE2B b44ae3c94584f37930bdec76ea6c94e4d62ce7b5c1b33c980e7fa0f803b80e1bf030118bfa9c0cc57b0f0a5e385ada97543db0d4671e9f01fc22449244d73d5b SHA512 fb81c3a8d545d0b1f3e68d8ab91e96e96073c5faba449ccae2088018f78eece840c8b64d361fff1f674263cb62358d30861df2d3575291290971a89075a52edb
diff --git a/media-gfx/opencsg/opencsg-1.8.1.ebuild b/media-gfx/opencsg/opencsg-1.8.1.ebuild
new file mode 100644
index 0000000000000..53183bb8fef64
--- /dev/null
+++ b/media-gfx/opencsg/opencsg-1.8.1.ebuild
@@ -0,0 +1,44 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit cmake
+
+MY_P="OpenCSG-${PV}"
+
+DESCRIPTION="The Constructive Solid Geometry rendering library"
+HOMEPAGE="https://www.opencsg.org"
+SRC_URI="https://www.opencsg.org/${MY_P}.tar.gz"
+S="${WORKDIR}/${MY_P}"
+
+LICENSE="GPL-2+"
+SLOT="0/$(ver_cut 1-2)"
+KEYWORDS="~amd64 ~arm64 ~ppc64 ~riscv ~x86"
+IUSE="doc"
+RESTRICT="test"
+
+DOCS=(
+	build.txt
+	changelog.txt
+)
+
+src_configure() {
+	local mycmakeargs=(
+		-DBUILD_EXAMPLE="no"
+	)
+
+	cmake_src_configure
+}
+
+src_install() {
+	cmake_src_install
+
+	if use doc; then
+		local HTML_DOCS=(
+			doc/.
+		)
+	fi
+
+	einstalldocs
+}