diff --git a/sci-libs/gsl/gsl-2.7.1-r2.ebuild b/sci-libs/gsl/gsl-2.7.1-r2.ebuild
index 62c11d0d8578f..ddc7239a72ceb 100644
--- a/sci-libs/gsl/gsl-2.7.1-r2.ebuild
+++ b/sci-libs/gsl/gsl-2.7.1-r2.ebuild
@@ -1,4 +1,4 @@
-# Copyright 1999-2023 Gentoo Authors
+# Copyright 1999-2024 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=8
@@ -36,6 +36,12 @@ src_prepare() {
 }
 
 src_configure() {
+	# -Werror=lto-type-mismatch
+	# https://bugs.gentoo.org/927585
+	#
+	# Testsuite issue. Seems fixed in 2.8.
+	filter-lto
+
 	filter-flags -ffast-math
 
 	if use cblas-external; then
diff --git a/sci-libs/gsl/gsl-2.7.1-r3.ebuild b/sci-libs/gsl/gsl-2.7.1-r3.ebuild
index 81205249e8734..e3b8d92fe4849 100644
--- a/sci-libs/gsl/gsl-2.7.1-r3.ebuild
+++ b/sci-libs/gsl/gsl-2.7.1-r3.ebuild
@@ -37,6 +37,12 @@ src_prepare() {
 }
 
 src_configure() {
+	# -Werror=lto-type-mismatch
+	# https://bugs.gentoo.org/927585
+	#
+	# Testsuite issue. Seems fixed in 2.8.
+	filter-lto
+
 	filter-flags -ffast-math
 
 	if use cblas-external; then