diff --git a/.gitignore b/.gitignore
index 98100ba..03aa02f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,3 @@
 /xtb-6.5.1.tar.gz
 /xtb-6.6.0.tar.gz
 /xtb-6.6.1.tar.gz
-/xtb-6.7.1.tar.gz
diff --git a/sources b/sources
index dfbc350..119d811 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (xtb-6.7.1.tar.gz) = b14d3a2965f2c5fa9faa25326d13e6f53f0b9df82141928e11de929a13c490673f5f209e26f7c9907073ee8da1a55d13473c06d9a3b079afed0dd5296ba051b5
+SHA512 (xtb-6.6.1.tar.gz) = 0a5b05be23fbc58f4c74abd6b0a10e5eb9a300b85cc065b9b6ef3d8e25cabfc04ee55ae2eafb6adaead6beddd1a8958ed547e1631131db0b71f1157c2df72dc2
diff --git a/xtb-6.7.1-formatting.patch b/xtb-6.7.1-formatting.patch
deleted file mode 100644
index 3616c9a..0000000
--- a/xtb-6.7.1-formatting.patch
+++ /dev/null
@@ -1,12 +0,0 @@
-diff -up xtb-6.7.1/src/optimizer.f90.formatting xtb-6.7.1/src/optimizer.f90
---- xtb-6.7.1/src/optimizer.f90.formatting	2024-07-23 20:08:02.000000000 +0000
-+++ xtb-6.7.1/src/optimizer.f90	2025-09-21 13:40:52.804499013 +0000
-@@ -849,7 +849,7 @@ subroutine relax(env,iter,mol,anc,restar
-       write(env%unit,'(5x,"change   ",e18.7,1x,"Eh")')                      echng
-       write(env%unit,'(3x,"gradient norm :",f14.7,1x,"Eh/α")',advance='no') gnorm
-       write(env%unit,'(3x,"predicted",e18.7)',advance='no')                 depred
--      write(env%unit,'(1x,"("f7.2"%)")')         (depred-echng)/echng*100
-+      write(env%unit,'(1x,"(",f7.2,"%)")')         (depred-echng)/echng*100
-    endif
-    
-    ! check 0 energy case !
diff --git a/xtb.spec b/xtb.spec
index 915cd06..3482fb2 100644
--- a/xtb.spec
+++ b/xtb.spec
@@ -8,14 +8,11 @@
 %global blasvar o
 %endif
 
-# avoid bash/tcsh dependencies from config_env scripts
-%global __requires_exclude_from ^%{_datadir}/xtb/.*$
-
 Name:           xtb
-Version:        6.7.1
-Release:        7%{?dist}
+Version:        6.6.1
+Release:        1%{?dist}
 Summary:        Semiempirical Extended Tight-Binding Program Package
-License:        LGPL-3.0-or-later
+License:        LGPLv3+
 URL:            https://github.com/grimme-lab/xtb/
 Source0:        https://github.com/grimme-lab/xtb/archive/v%{version}/xtb-%{version}.tar.gz
 
@@ -23,8 +20,6 @@ Source0:        https://github.com/grimme-lab/xtb/archive/v%{version}/xtb-%{vers
 Patch0:         xtb-6.5.1-fedora.patch
 # Add sanity checks to environment variables, https://github.com/grimme-lab/xtb/pull/317
 Patch4:         xtb-6.3.2-environment.patch
-# Fix fortran formatting, issue was fixed upstream in #1278
-Patch5:         xtb-6.7.1-formatting.patch
 
 BuildRequires:  gcc-gfortran
 BuildRequires:  meson
@@ -34,10 +29,9 @@ BuildRequires:  %{blaslib}-devel
 BuildRequires:  rubygem-asciidoctor
 # The program queries $HOSTNAME at runtime and so fails to run in mock without this
 BuildRequires:  hostname
+# New in 6.5.0
 BuildRequires:  mctc-lib-devel
 BuildRequires:  test-drive-devel
-BuildRequires:  multicharge-devel
-BuildRequires:  dftd4-devel
 
 # Tests fail on s390x for some reason
 ExcludeArch:    s390x
@@ -76,13 +70,11 @@ This package contains development headers for xtb.
 %setup -q
 %patch 0 -p1 -b .fedoraver
 %patch 4 -p1 -b .env
-%patch 5 -p1 -b .formatting
 
 %build
-export FFLAGS="$FFLAGS -fPIC"
-export FCFLAGS="$FCFLAGS -fPIC"
-# TODO: tblite and cpcm-x support should ideally be turned on, but the packages are not yet in Fedora
-%meson -Dlapack=custom -Dcustom_libraries=%{blaslib}%{blasvar} -Dtblite=disabled -Dcpcmx=disabled
+export FFLAGS="%{optflags} -I%{_fmoddir} -fPIC"
+export FCLAGS="%{optflags} -I%{_fmoddir} -fPIC"
+%meson -Dlapack=custom -Dcustom_libraries=%{blaslib}%{blasvar} -Dtblite=disabled
 date=$(date)
 # Create customized Fedora versioning
 cat > %{_vpath_builddir}/xtb_version.fh <<EOF
@@ -90,8 +82,6 @@ character(len=*),parameter :: version = "%{version}-%{release}%{dist}"
 character(len=*),parameter :: date = "$date"
 character(len=*),parameter :: author = "Fedora project"
 EOF
-# Meson dependency workaround from BZ #2390464
-ninja -C %{_vpath_builddir} -j %{_smp_build_ncpus} %{?__meson_verbose:--verbose} libxtb.a
 %meson_build
 
 %install
@@ -142,39 +132,6 @@ export OMP_NUM_THREADS=1
 %{_libdir}/pkgconfig/xtb.pc
 
 %changelog
-* Fri Jul 17 2026 Fedora Release Engineering <releng@fedoraproject.org> - 6.7.1-7
-- Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild
-
-* Sat Jan 17 2026 Fedora Release Engineering <releng@fedoraproject.org> - 6.7.1-6
-- Rebuilt for https://fedoraproject.org/wiki/Fedora_44_Mass_Rebuild
-
-* Sun Sep 21 2025 Susi Lehtola <jussilehtola@fedoraproject.org> - 6.7.1-5
-- Patch out formatting issue in code that causes a crash.
-
-* Mon Sep 15 2025 Susi Lehtola <jussilehtola@fedoraproject.org> - 6.7.1-4
-- Fix FTBFS caused by lack of dependency tracking in meson (BZ #2390464)
-
-* Fri Jul 25 2025 Fedora Release Engineering <releng@fedoraproject.org> - 6.7.1-3
-- Rebuilt for https://fedoraproject.org/wiki/Fedora_43_Mass_Rebuild
-
-* Sun Jan 19 2025 Fedora Release Engineering <releng@fedoraproject.org> - 6.7.1-2
-- Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild
-
-* Fri Sep 13 2024 Susi Lehtola <jussilehtola@fedoraproject.org> - 6.7.1-1
-- Update to 6.7.1.
-
-* Sat Jul 20 2024 Fedora Release Engineering <releng@fedoraproject.org> - 6.6.1-5
-- Rebuilt for https://fedoraproject.org/wiki/Fedora_41_Mass_Rebuild
-
-* Wed Jul 17 2024 Miroslav Suchý <msuchy@redhat.com> - 6.6.1-4
-- convert license to SPDX
-
-* Mon Jan 29 2024 Fedora Release Engineering <releng@fedoraproject.org> - 6.6.1-3
-- Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild
-
-* Sat Jan 27 2024 Fedora Release Engineering <releng@fedoraproject.org> - 6.6.1-2
-- Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild
-
 * Mon Aug 14 2023 Susi Lehtola <jussilehtola@fedoraproject.org> - 6.6.1-1
 - Update to 6.6.1.