diff --git a/dev-libs/libixion/files/libixion-0.19.0-boost-m4.patch b/dev-libs/libixion/files/libixion-0.19.0-boost-m4.patch
new file mode 100644
index 0000000000000..1771e40e262fd
--- /dev/null
+++ b/dev-libs/libixion/files/libixion-0.19.0-boost-m4.patch
@@ -0,0 +1,31 @@
+Minimal diff from upstream boost.m4 (https://github.com/tsuna/boost.m4)
+to make things work with >=boost-1.89.0, which made boost_system a
+header-only library.
+
+--- a/m4/boost.m4~
++++ b/m4/boost.m4
+@@ -1130,15 +1130,20 @@ BOOST_DEFUN([String_Algo],
+ ])
+ 
+ 
+-# BOOST_SYSTEM([PREFERRED-RT-OPT])
++# BOOST_SYSTEM([PREFERRED-RT-OPT], [ERROR_ON_UNUSABLE])
+ # --------------------------------
+ # Look for Boost.System.  For the documentation of PREFERRED-RT-OPT, see the
+ # documentation of BOOST_FIND_LIB above.  This library was introduced in Boost
+-# 1.35.0.
++# 1.35.0 and is header only since 1.70.
+ BOOST_DEFUN([System],
+-[BOOST_FIND_LIB([system], [$1],
++[
++if test $boost_major_version -ge 170; then
++  BOOST_FIND_HEADER([boost/system/error_code.hpp])
++else
++  BOOST_FIND_LIB([system], [$1],
+                 [boost/system/error_code.hpp],
+-                [boost::system::error_code e; e.clear();])
++                [boost::system::error_code e; e.clear();], [], [], [$2])
++fi
+ ])# BOOST_SYSTEM
+ 
+ 
diff --git a/dev-libs/libixion/files/libixion-0.20.0-boost-m4.patch b/dev-libs/libixion/files/libixion-0.20.0-boost-m4.patch
new file mode 100644
index 0000000000000..31d2bdd7173ac
--- /dev/null
+++ b/dev-libs/libixion/files/libixion-0.20.0-boost-m4.patch
@@ -0,0 +1,30 @@
+Minimal diff from upstream boost.m4 (https://github.com/tsuna/boost.m4)
+to make things work with >=boost-1.89.0, which made boost_system a
+header-only library.
+
+--- a/m4/boost.m4~
++++ b/m4/boost.m4
+@@ -1328,15 +1328,20 @@ BOOST_DEFUN([String_Algo],
+ ])
+ 
+ 
+-# BOOST_SYSTEM([PREFERRED-RT-OPT], [ERROR_ON_UNUSABLE])
++ BOOST_SYSTEM([PREFERRED-RT-OPT], [ERROR_ON_UNUSABLE])
+ # --------------------------------
+ # Look for Boost.System.  For the documentation of PREFERRED-RT-OPT, see the
+ # documentation of BOOST_FIND_LIB above.  This library was introduced in Boost
+-# 1.35.0.
++# 1.35.0 and is header only since 1.70.
+ BOOST_DEFUN([System],
+-[BOOST_FIND_LIB([system], [$1],
++[
++if test $boost_major_version -ge 170; then
++  BOOST_FIND_HEADER([boost/system/error_code.hpp])
++else
++  BOOST_FIND_LIB([system], [$1],
+                 [boost/system/error_code.hpp],
+                 [boost::system::error_code e; e.clear();], [], [], [$2])
++fi
+ ])# BOOST_SYSTEM
+ 
+ 
diff --git a/dev-libs/libixion/libixion-0.19.0-r2.ebuild b/dev-libs/libixion/libixion-0.19.0-r2.ebuild
new file mode 100644
index 0000000000000..866737084bd7c
--- /dev/null
+++ b/dev-libs/libixion/libixion-0.19.0-r2.ebuild
@@ -0,0 +1,63 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{11..14} )
+inherit autotools python-single-r1
+
+DESCRIPTION="General purpose formula parser & interpreter"
+HOMEPAGE="https://gitlab.com/ixion/ixion"
+
+if [[ ${PV} == *9999* ]]; then
+	MDDS_SLOT="1/3.0"
+	EGIT_REPO_URI="https://gitlab.com/ixion/ixion.git"
+	inherit git-r3
+else
+	MDDS_SLOT="1/2.1"
+	SRC_URI="https://kohei.us/files/ixion/src/${P}.tar.xz"
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~ppc ~ppc64 ~riscv ~x86"
+fi
+
+LICENSE="MIT"
+SLOT="0/0.18" # based on SONAME of libixion.so
+IUSE="debug python"
+
+REQUIRED_USE="python? ( ${PYTHON_REQUIRED_USE} )"
+
+RDEPEND="
+	dev-libs/boost:=
+	dev-util/mdds:${MDDS_SLOT}
+	python? ( ${PYTHON_DEPS} )
+"
+DEPEND="${RDEPEND}"
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-0.19.0-gcc15-cstdint.patch # bug 937388
+	"${FILESDIR}"/${PN}-0.19.0-fix-win32-ifdef.patch # bug 939807
+	"${FILESDIR}"/${PN}-0.19.0-boost-m4.patch # bug 961528
+)
+
+pkg_setup() {
+	use python && python-single-r1_pkg_setup
+}
+
+src_prepare() {
+	default
+	eautoreconf
+}
+
+src_configure() {
+	local myeconfargs=(
+		$(use_enable debug)
+		$(use_enable debug debug-utils)
+		$(use_enable debug log-debug)
+		$(use_enable python)
+	)
+	econf "${myeconfargs[@]}"
+}
+
+src_install() {
+	default
+	find "${D}" -name '*.la' -type f -delete || die
+}
diff --git a/dev-libs/libixion/libixion-0.20.0.ebuild b/dev-libs/libixion/libixion-0.20.0.ebuild
index 3cec71c51dd9a..5779d9590f205 100644
--- a/dev-libs/libixion/libixion-0.20.0.ebuild
+++ b/dev-libs/libixion/libixion-0.20.0.ebuild
@@ -3,8 +3,8 @@
 
 EAPI=8
 
-PYTHON_COMPAT=( python3_{10..13} )
-inherit libtool python-single-r1
+PYTHON_COMPAT=( python3_{11..14} )
+inherit autotools python-single-r1
 
 DESCRIPTION="General purpose formula parser & interpreter"
 HOMEPAGE="https://gitlab.com/ixion/ixion"
@@ -12,7 +12,7 @@ HOMEPAGE="https://gitlab.com/ixion/ixion"
 if [[ ${PV} == *9999* ]]; then
 	MDDS_SLOT="1/3.0"
 	EGIT_REPO_URI="https://gitlab.com/ixion/ixion.git"
-	inherit git-r3 autotools
+	inherit git-r3
 else
 	MDDS_SLOT="1/2.1"
 	# Invalid as of 0.20.0, serves HTML
@@ -34,17 +34,17 @@ RDEPEND="
 "
 DEPEND="${RDEPEND}"
 
+PATCHES=(
+	"${FILESDIR}"/${PN}-0.20.0-boost-m4.patch # bug 961528
+)
+
 pkg_setup() {
 	use python && python-single-r1_pkg_setup
 }
 
 src_prepare() {
 	default
-	if [[ ${PV} == *9999* ]]; then
-		eautoreconf
-	else
-		elibtoolize
-	fi
+	eautoreconf
 }
 
 src_configure() {
diff --git a/dev-libs/libixion/libixion-9999.ebuild b/dev-libs/libixion/libixion-9999.ebuild
index 3cec71c51dd9a..0bf18a87fd5eb 100644
--- a/dev-libs/libixion/libixion-9999.ebuild
+++ b/dev-libs/libixion/libixion-9999.ebuild
@@ -3,7 +3,7 @@
 
 EAPI=8
 
-PYTHON_COMPAT=( python3_{10..13} )
+PYTHON_COMPAT=( python3_{11..14} )
 inherit libtool python-single-r1
 
 DESCRIPTION="General purpose formula parser & interpreter"