diff --git a/net-im/mattermost-desktop-bin/Manifest b/net-im/mattermost-desktop-bin/Manifest
index 504befbbef821..4777ea2891391 100644
--- a/net-im/mattermost-desktop-bin/Manifest
+++ b/net-im/mattermost-desktop-bin/Manifest
@@ -2,3 +2,5 @@ DIST mattermost-desktop-5.12.1-linux-arm64.tar.gz 110206341 BLAKE2B 98179857b164
 DIST mattermost-desktop-5.12.1-linux-x64.tar.gz 110194182 BLAKE2B a5cfe177cbe0d0b00de3c5b0030f456c1a12d3848ef832e3fee180f3d9e14b9b54f49d886c2443a614af5afbd3138b78fe9ce171b48ff7ec69a536c1772bea87 SHA512 5f246ed53cacd5dff2942ababa62d3993e3fa1902ee53370b378b98a3c80f32172dee93c130f8c5274bc2772e717491fa89e613b1979090fc5daca6d5dcafb42
 DIST mattermost-desktop-5.13.0-linux-arm64.tar.gz 113506927 BLAKE2B 24d604d89bb237a0bd18b8f08deb4632836272c00f1010884da9156c97d90ded910b2a4d060b82e31537000c598f0c2433fa8497998257f73a744def492c5bc5 SHA512 10cf7e3ff16f9c48da5e816101ad8de7345510fc47bade5861c3d87e2c9552560305273b042cf7926f470672fc30026b1af137d1ddf0ea0bd4945618cae3bb2c
 DIST mattermost-desktop-5.13.0-linux-x64.tar.gz 113480147 BLAKE2B 878b710c68cf3bd03f9f3ae694cd146ccec1dd3880102bd6718bc511c6dd67b6664f5cfe9e0431b6253276423c5086794e989eb937db7ada0b5d3cbca514e413 SHA512 26003bb71f7be311984aded97bd67316c5f74a9abb5dca0f28589fca67c1b154e08acc1c18b9a4c3afdfee6a35bd14b9366373935bf978124e51392cff404b6c
+DIST mattermost-desktop-5.13.1-rc.1-linux-arm64.tar.gz 113507163 BLAKE2B f57cc5dda059209c1a25cc73e473027d76aa052079f50f66d7ee19ad051090c4bcc85df414d6c132adc8d2f667c2839bca13414b4caf613d16b4a50a07c6606b SHA512 0bb243b34d0ed930aad2a56b3b65f4f71ab5c1deef6e3f0e33abcd2cbf55a9b15b1c355c210210db0fc23b8188d5d166b7baf48f9e536debd92ef6a54771617f
+DIST mattermost-desktop-5.13.1-rc.1-linux-x64.tar.gz 113480656 BLAKE2B 7ecbcd0b1e82ff98f7fb7a35e934d484dbb05631cfdc47ced7dd575c47c38a2ad225de4bda919f159770b2698ca1b430f44076441e66292e2fcb9dd0bab463ed SHA512 e1d42eed1b81f55916aa4ffbd5c1b5a1654afce898cbdc5304d4b3e3d9e42b3d6bccb11cf71ddbeae2018f1afeb7b0ad6961f0d60332cfa93b82cb79d795dfac
diff --git a/net-im/mattermost-desktop-bin/mattermost-desktop-bin-5.13.1_rc1.ebuild b/net-im/mattermost-desktop-bin/mattermost-desktop-bin-5.13.1_rc1.ebuild
new file mode 100644
index 0000000000000..befb8df8dd100
--- /dev/null
+++ b/net-im/mattermost-desktop-bin/mattermost-desktop-bin-5.13.1_rc1.ebuild
@@ -0,0 +1,114 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+MY_PN="${PN%-*}"
+MY_PV="${PV/_rc/-rc.}"
+
+inherit desktop toolchain-funcs xdg
+
+DESCRIPTION="Mattermost Desktop application"
+HOMEPAGE="https://mattermost.com/"
+
+SRC_URI="
+	amd64? ( https://releases.mattermost.com/desktop/${MY_PV}/mattermost-desktop-${MY_PV}-linux-x64.tar.gz )
+	arm64? ( https://releases.mattermost.com/desktop/${MY_PV}/mattermost-desktop-${MY_PV}-linux-arm64.tar.gz )
+"
+S="${WORKDIR}"
+
+LICENSE="Apache-2.0 GPL-2+ LGPL-2.1+ MIT"
+SLOT="0"
+# Starting with 5.2.0 upstream dropped x86 for their binary release #879519
+if [[ ${PV} != *rc* ]]; then
+	KEYWORDS="~amd64 ~arm64"
+fi
+
+RDEPEND="
+	>=app-accessibility/at-spi2-core-2.46.0:2[X]
+	dev-libs/expat
+	dev-libs/glib:2
+	dev-libs/nspr
+	dev-libs/nss
+	dev-libs/wayland
+	media-libs/alsa-lib
+	media-libs/mesa
+	net-print/cups
+	sys-apps/dbus
+	sys-libs/glibc
+	virtual/libudev
+	x11-libs/cairo
+	x11-libs/gdk-pixbuf:2
+	x11-libs/gtk+:3[X]
+	x11-libs/libX11
+	x11-libs/libXcomposite
+	x11-libs/libXdamage
+	x11-libs/libXext
+	x11-libs/libXfixes
+	x11-libs/libXrandr
+	x11-libs/libdrm
+	x11-libs/libxcb
+	x11-libs/libxkbcommon
+	x11-libs/pango
+"
+
+BDEPEND="
+	dev-util/debugedit
+"
+
+QA_PREBUILT="
+	opt/mattermost-desktop/mattermost-desktop
+	opt/mattermost-desktop/libnode.so
+	opt/mattermost-desktop/libffmpeg.so
+	opt/mattermost-desktop/libGLESv2.so
+	opt/mattermost-desktop/libEGL.so
+	opt/mattermost-desktop/libvk_swiftshader.so
+	opt/mattermost-desktop/libvulkan.so.1
+	opt/mattermost-desktop/resources/*
+"
+
+DOCS=(
+	NOTICE.txt
+)
+
+src_prepare() {
+	default
+
+	# file collision with FEATURES=splitdebug, see bug #961437
+	tc-export OBJCOPY
+	find . -type f ! -name '*$(*)*' -print0 | while IFS= read -r -d '' file; do
+		if file "${file}" | grep -qE "ELF (32|64)-bit"; then
+			${OBJCOPY} --remove-section .note.gnu.build-id "${file}" || die
+			debugedit -b "${EPREFIX}/opt/${MY_PN}" -d "/usr/lib/debug" -i "${file}" || die
+		fi
+	done
+}
+
+src_install() {
+	if use amd64; then
+		cd mattermost-desktop-${MY_PV}-linux-x64 || die
+	elif use arm64; then
+		cd mattermost-desktop-${MY_PV}-linux-arm64 || die
+	fi
+	newicon app_icon.png ${MY_PN}.png
+
+	insinto "/opt/${MY_PN}/locales"
+	doins locales/*.pak
+
+	insinto "/opt/${MY_PN}/resources"
+	doins -r resources/*.asar*
+
+	insinto "/opt/${MY_PN}"
+	doins *.pak *.bin *.dat
+	exeinto "/opt/${MY_PN}"
+	doexe *.so *.so.* "${MY_PN}"
+
+	dosym -r "/opt/${MY_PN}/${MY_PN}" "/usr/bin/${MY_PN}"
+
+	make_desktop_entry \
+		"${MY_PN} --enable-features=WaylandWindowDecorations --ozone-platform-hint=auto %U" \
+		Mattermost "${MY_PN}" "Network;InstantMessaging;" \
+		"MimeType=x-scheme-handler/mattermost;\nStartupWMClass=Mattermost"
+
+	einstalldocs
+}