diff --git a/giac.spec b/giac.spec
index 2b02ecc..b979c4d 100644
--- a/giac.spec
+++ b/giac.spec
@@ -2,6 +2,10 @@
 # See http://pcm1.e.ujf-grenoble.fr/forum/viewtopic.php?f=19&t=1733&sid=3257f5085f4ae208dc36665f2873252f
 %bcond_with check
 
+%if 0%{?fedora} >= 33
+%bcond_without flexiblas
+%endif
+
 %global subversion .7
 
 Name:          giac
@@ -40,7 +44,11 @@ BuildRequires: libnauty-devel
 BuildRequires: mpfr-devel
 BuildRequires: ntl-devel
 BuildRequires: pari-devel
-BuildRequires: lapack-devel
+%if %{with flexiblas}
+BuildRequires:  flexiblas-devel
+%else
+BuildRequires:  blas-devel, lapack-devel
+%endif
 BuildRequires: mpfi-devel
 BuildRequires: mesa-libGL-devel
 BuildRequires: libao-devel
@@ -168,6 +176,11 @@ rm -f examples/Exemples/analyse/._*
 %build
 export CXXFLAGS="-std=c++14 $RPM_OPT_FLAGS"
 
+%if %{with flexiblas}
+sed -e 's|LIB(blas|LIB(flexiblas|g' -e 's|LIB(lapack|LIB(flexiblas|g' -i configure.in
+sed -e 's|-lblas|-lflexiblas|g' -e 's|-llapack|-lflexiblas|g' -i configure
+%endif
+
 %configure --enable-static=no --with-included-gettext=no --enable-nls=yes \
  --enable-tommath=no --enable-debug=no --enable-gc=no --enable-sscl=no \
  --enable-dl=yes --enable-gsl=yes --enable-lapack=yes --enable-pari=yes \
@@ -392,6 +405,9 @@ make -C check check
 %{_datadir}/giac/examples/
 
 %changelog
+* Thu Aug 27 2020 Iñaki Úcar <iucar@fedoraproject.org> - 1.6.0.7-5
+- https://fedoraproject.org/wiki/Changes/FlexiBLAS_as_BLAS/LAPACK_manager
+
 * Tue Aug 18 2020 Jeff Law <law@redhat.com> - 1.6.0.7-4
 - Force C++14 as this code is not C++17 ready