diff --git a/sci-libs/cgcode/cgcode-1.0-r2.ebuild b/sci-libs/cgcode/cgcode-1.0-r2.ebuild
index 90160c444ea99..931a56954eb32 100644
--- a/sci-libs/cgcode/cgcode-1.0-r2.ebuild
+++ b/sci-libs/cgcode/cgcode-1.0-r2.ebuild
@@ -1,9 +1,9 @@
-# Copyright 1999-2015 Gentoo Foundation
+# Copyright 1999-2021 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=5
 
-inherit eutils fortran-2 toolchain-funcs
+inherit eutils fortran-2 flag-o-matic toolchain-funcs
 
 DESCRIPTION="Conjugate gradient Codes for large sparse linear systems"
 HOMEPAGE="http://fetk.org/codes/cgcode/index.html"
@@ -23,6 +23,10 @@ S="${WORKDIR}"/${PN}
 src_prepare() {
 	epatch "${FILESDIR}"/${PV}-gentoo.patch
 
+	# GCC 10 workaround
+	# bug #722000
+	append-fflags $(test-flags-FC -fallow-argument-mismatch)
+
 	cat >> make.inc <<- EOF
 	F77 = $(tc-getFC)
 	FFLAGS = ${FFLAGS}