diff --git a/dev-cpp/eigen/Manifest b/dev-cpp/eigen/Manifest
index a1e4983e7c419..e78035ce5e3c5 100644
--- a/dev-cpp/eigen/Manifest
+++ b/dev-cpp/eigen/Manifest
@@ -1,4 +1,6 @@
 DIST eigen-3.4.0.tar.bz2 2143091 BLAKE2B a32aac13cbab68cfaaa252d8a406e6a36ecfd1239361412b1f9baa08284a94467479c08ffae10cb847e9916472b46b1c1af4efbf81f957c8200a4379acd42c42 SHA512 cc488eb111e0e248744d2bc4475b345b5fb82361dff226a5b73a33bd0388de8c219cff8cffcf8f476b672fc0e223f339e8c6a1cfb6293840a4a6abf232438a89
 DIST eigen-3.4.1.tar.bz2 2157363 BLAKE2B 382fcebd716d81019c4606974f8db22234ff34c415d465eb5cf9dbab34d4fa9bca7a3ae6ef64a7eca627cdbacb35fdac862005b0a14ec2d851831246f879f374 SHA512 806be7536f811eb77898a9431eac4fe446fbdd41c2a33ebe30e56750920c105e24bc41d8cbb4a5c01ee770ded9c58f06ff37058d17c6e2301bc9021a864bb549
+DIST eigen-3.4.1_p1.patch 1007 BLAKE2B 0a2af4c2cd8fc423535e046919fe7f931e9b718df1ff799ccc451139c084a344988fc8d1277fd1970827051ce1fcae5512222310fea00a9f1a654f3b1cffbec8 SHA512 ec3f6c78c19544f9a4f2c52e069b573eb633d67998acdd7d74e9769102ec9dfdbf68fca1492002ed0ec6b3e9a25637afa9978cfb80dd3e3f9aa0e1a34ac64534
+DIST eigen-3.4.1_p2.patch 1054 BLAKE2B b46683962764a9dd560932e2230177f91e56d9e4b48ce7de79cad5743b59050aafde4f2da1db961adfb5228ac17f477e598cdf23c4150fa254d2640e4fff3a6d SHA512 bdcd4599ccb88f0599aa74fd5a73135dcc5bb9ad0bc2791517473a48f938bb784e62376e829b8b5b3d6f5149bc8874bf77655c1bfe63f86afbc151c2c86d6732
 DIST eigen-5.0.1.tar.bz2 2335713 BLAKE2B a7ccf9fc63b25b0e5ad8940ccf541cf4977a80ded671757ae1965cd0ca480fd11361de8eaf18cae94a74cde68979a76f5a18b47b696cdd6939b6cf30922e5fd4 SHA512 5cb11c7f1945ae7f36c5deb067b8d5a962d2d3cff7d4dbec8a4ee255ee6aae1b7dbe6d5a6dcc6fe77554ef191e4101366bf79cfb34f5cf06a0e4de311afbeaf6
 DIST eigen-lapack_addons-3.4.1.tgz 6215074 BLAKE2B 564c3398de1f4ea249b58957a482cda0b5eb99e5021e1f18abf3b4d2893fed48912bfa8386681fcae03dd933eea91644f7429d47a53684d64462209a6ae76f30 SHA512 5a827d0befb521cb430f0d63f5000e7955359bc637cdb7292d942712e98c0702570a5b650a72fc609bf5b43633661c0e51de7761ae892df6ff0aab667f436edf
diff --git a/dev-cpp/eigen/eigen-3.4.1.ebuild b/dev-cpp/eigen/eigen-3.4.1.ebuild
index e7ea43d6362d2..3129f0e889d2c 100644
--- a/dev-cpp/eigen/eigen-3.4.1.ebuild
+++ b/dev-cpp/eigen/eigen-3.4.1.ebuild
@@ -24,8 +24,11 @@ if [[ ${PV} = *9999* ]] ; then
 		EGIT_BRANCH="$(ver_cut 1-2)"
 	fi
 else
+	# we backport two patches from the 3.4 branch
 	SRC_URI="
 		https://gitlab.com/lib${PN}/${PN}/-/archive/${PV}/${P}.tar.bz2
+		https://gitlab.com/libeigen/eigen/-/commit/0295f81a835ef69e2bacd9e75ab5782eca398720.patch -> ${P}_p1.patch
+		https://gitlab.com/libeigen/eigen/-/commit/28ded8800c26864e537852658428ab44c8399e87.patch -> ${P}_p2.patch
 	"
 	KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~arm64-macos ~x64-macos"
 fi
@@ -225,6 +228,9 @@ PATCHES=(
 
 	"${FILESDIR}/${PN}-5.0.1-cmake-GNUInstallDirs.patch"
 	"${FILESDIR}/${PN}-5.0.1-Do-not-show-deprecated-CUDA-device-properties-for-CU.patch"
+
+	"${DISTDIR}/${P}_p1.patch"
+	"${DISTDIR}/${P}_p2.patch"
 )
 
 # TODO should be in cuda.eclass