diff --git a/dev-ruby/mutex_m/Manifest b/dev-ruby/mutex_m/Manifest
new file mode 100644
index 0000000000000..7edcf85a3ab18
--- /dev/null
+++ b/dev-ruby/mutex_m/Manifest
@@ -0,0 +1 @@
+DIST mutex_m-0.2.0.tar.gz 4199 BLAKE2B 853b68f856d43ac7172e9c4fc8dd144282e6879b75bdcb223c40ca0433e22c21e2343cb949c19d6aaafb9208650001b011e12954321e1223f40a3bbb62a8fbde SHA512 aba0c77ac7663925a856621dad89ed6afd9a70697373bbffa0c335a9aef4774c4114b45e4addd747fe2b751af689c2710e549398aa80176970c612d570730ee7
diff --git a/dev-ruby/mutex_m/metadata.xml b/dev-ruby/mutex_m/metadata.xml
new file mode 100644
index 0000000000000..420f235d2335a
--- /dev/null
+++ b/dev-ruby/mutex_m/metadata.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
+<pkgmetadata>
+  <maintainer type="project">
+    <email>ruby@gentoo.org</email>
+    <name>Gentoo Ruby Project</name>
+  </maintainer>
+  <upstream>
+    <remote-id type="github">ruby/mutex_m</remote-id>
+    <remote-id type="rubygems">mutex_m</remote-id>
+  </upstream>
+</pkgmetadata>
diff --git a/dev-ruby/mutex_m/mutex_m-0.2.0.ebuild b/dev-ruby/mutex_m/mutex_m-0.2.0.ebuild
new file mode 100644
index 0000000000000..d06d22d412e75
--- /dev/null
+++ b/dev-ruby/mutex_m/mutex_m-0.2.0.ebuild
@@ -0,0 +1,25 @@
+# Copyright 1999-2023 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+USE_RUBY="ruby31 ruby32 ruby33"
+
+RUBY_FAKEGEM_BINWRAP=""
+RUBY_FAKEGEM_EXTRADOC="README.md"
+RUBY_FAKEGEM_GEMSPEC="mutex_m.gemspec"
+
+inherit ruby-fakegem
+
+DESCRIPTION="Mixin to extend objects to be handled like a Mutex"
+HOMEPAGE="https://github.com/ruby/mutex_m"
+SRC_URI="https://github.com/ruby/mutex_m/archive/v${PV}.tar.gz -> ${P}.tar.gz"
+
+LICENSE="BSD-2"
+SLOT="$(ver_cut 1-2)"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~x64-solaris"
+IUSE=""
+
+all_ruby_prepare() {
+	sed -e 's:_relative ": "./:' \
+		-i ${RUBY_FAKEGEM_GEMSPEC} || die
+}