diff --git a/net-im/mattermost-desktop-bin/Manifest b/net-im/mattermost-desktop-bin/Manifest
index a349799790949..ab12eb1b6a695 100644
--- a/net-im/mattermost-desktop-bin/Manifest
+++ b/net-im/mattermost-desktop-bin/Manifest
@@ -1,2 +1,4 @@
 DIST mattermost-desktop-5.13.2-linux-arm64.tar.gz 114103498 BLAKE2B d318786dd11f048c5fe3e4eacbcef817706ce187e9c127c08e5d9a4fe4d20bcfe16200dc8fe44cff041e0818d3a1ace7db4f0dfa62cf14a9cf8418b89c00ee10 SHA512 64bfa4c8d5934d37b713dd763179b90d001b67d41e72ffe24c9e20a19d931e810ba4299cb75e2dd122ffcf3d5c2541102d13b150e58dc3caf7ee94be83a9d068
 DIST mattermost-desktop-5.13.2-linux-x64.tar.gz 114110126 BLAKE2B 1d17c08f34f0b2375edfd18ff78036b488406460adb6907a02ce67b04094651223974ceed1ed66fef0d408b3236f468113ac4cfdfdebb6fbacd78a1cdb031a48 SHA512 65223bad16b4b4a0362db2cc8c9bd84fb1cc291eb30a072998ceda7b62bc9d317795c45764c41f464c5eae06fcc2537cbaa7d757ff7c885b0de7f44622e8eebd
+DIST mattermost-desktop-6.0.0-rc.1-linux-arm64.tar.gz 115419313 BLAKE2B 94da28c0565bbed088b1763cc0e878de9487d691a58a2499dbcacc4723fc3dc2b758df9683a1cae09621eff749713c5c943c6a6f11430578df30b8f6052f6408 SHA512 6e1dbaf53157ba7c46e6bba590478e46b7d8effd42ee91ba54b58f50719e18740120e323b49462a3a6ca363a1754844855d2f8c783b967e76ec61bc442940405
+DIST mattermost-desktop-6.0.0-rc.1-linux-x64.tar.gz 115390998 BLAKE2B aea8538ca5d5f0aa75f9090de192ecc7277f87cf99c2422cc693b9bbb50d6f96be6e296e6760d2dc6c4644a1465f1c14cb930aa69eaa97d53644d55f46f12874 SHA512 10998960cb0214e5b9e24d3535cbeb0f3921ce202c397412e114fa9ff2033dc571bacc31cdc5ba65e5f23691b926b5d5507541c69b0d0a2c8fabd283e852ebfb
diff --git a/net-im/mattermost-desktop-bin/mattermost-desktop-bin-6.0.0_rc1.ebuild b/net-im/mattermost-desktop-bin/mattermost-desktop-bin-6.0.0_rc1.ebuild
new file mode 100644
index 0000000000000..befb8df8dd100
--- /dev/null
+++ b/net-im/mattermost-desktop-bin/mattermost-desktop-bin-6.0.0_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
+}