diff --git a/lib/utils.pm b/lib/utils.pm
index b0c91ba4..f02d225d 100644
--- a/lib/utils.pm
+++ b/lib/utils.pm
@@ -504,13 +504,12 @@ sub disable_updates_repos {
         both => 0,
         @_
     );
-    my $nonmod = "updates-testing";
-    $nonmod .= " updates" if ($args{both});
-    assert_script_run "dnf config-manager --set-disabled $nonmod";
+    # FIXME as of 2023-06-20 dnf5 doesn't have config-manager plugin yet :(
+    assert_script_run 'sed -i -e "s,enabled=1,enabled=0,g" /etc/yum.repos.d/fedora-updates-testing.repo';
+    assert_script_run 'sed -i -e "s,enabled=1,enabled=0,g" /etc/yum.repos.d/fedora-updates.repo' if ($args{both});
     unless (script_run 'test -f /etc/yum.repos.d/fedora-updates-testing-modular.repo') {
-        my $mod = "updates-testing-modular";
-        $mod .= " updates-modular" if ($args{both});
-        assert_script_run "dnf config-manager --set-disabled $mod";
+        assert_script_run 'sed -i -e "s,enabled=1,enabled=0,g" /etc/yum.repos.d/fedora-updates-testing-modular.repo';
+        assert_script_run 'sed -i -e "s,enabled=1,enabled=0,g" /etc/yum.repos.d/fedora-updates-modular.repo' if ($args{both});
     }
 }
 
diff --git a/tests/desktop_update_graphical.pm b/tests/desktop_update_graphical.pm
index 120309f2..14f30be9 100644
--- a/tests/desktop_update_graphical.pm
+++ b/tests/desktop_update_graphical.pm
@@ -10,12 +10,13 @@ sub run {
     my $relnum = get_release_number;
     # use a tty console for repo config and package prep
     $self->root_console(tty => 3);
-    assert_script_run 'dnf config-manager --set-disabled updates-testing';
+    disable_updates_repos;
     # for update tests, disable koji-rawhide at this point, otherwise
     # gnome-software will complain about things being unsigned even
     # though the repo has gpgcheck=0
     if (get_var("ADVISORY_OR_TASK") && get_var("VERSION") eq get_var("RAWREL")) {
-        assert_script_run 'dnf config-manager --set-disabled koji-rawhide';
+        # FIXME as of 2023-06-20 dnf5 doesn't have config-manager plugin yet :(
+        assert_script_run 'sed -i -e "s,enabled=1,enabled=0,g" /etc/yum.repos.d/koji-rawhide.repo';
     }
     prepare_test_packages;
     # get back to the desktop