diff --git a/.tidyallrc b/.tidyallrc
index 718b4d8d..39457283 100644
--- a/.tidyallrc
+++ b/.tidyallrc
@@ -1,3 +1,7 @@
+[Flake8]
+ignore = tests/individually-importing/*
+select = **/*.py
+
 [PerlTidy]
 argv = -ci=4 -bl -cti=0
 ignore = **/{cmpdigest,valgrind,verify}--*.t
diff --git a/Makefile b/Makefile
index 649e158f..855bc55b 100644
--- a/Makefile
+++ b/Makefile
@@ -67,7 +67,8 @@ pretest:
 	@rm -f tests/individually-importing/*.py # To avoid stray files
 	python scripts/gen_individual_importing_tests.py
 
-TEST_ENV = PYTHONPATH="`pwd`:`pwd`/tests/lib"
+TEST_ENV_PATH = "`pwd`:`pwd`/tests/lib"
+TEST_ENV = PYTHONPATH=$(TEST_ENV_PATH) PERL5LIB=$(TEST_ENV_PATH)
 TEST_FILES = tests/style/*.t tests/unit-generated/*.py tests/individually-importing/*.py
 
 define RUN_TESTS
diff --git a/tests/lib/Code/TidyAll/Plugin/Flake8.pm b/tests/lib/Code/TidyAll/Plugin/Flake8.pm
new file mode 100644
index 00000000..14aaeb8e
--- /dev/null
+++ b/tests/lib/Code/TidyAll/Plugin/Flake8.pm
@@ -0,0 +1,51 @@
+package Code::TidyAll::Plugin::Flake8;
+
+use Moo;
+use String::ShellQuote qw/ shell_quote /;
+
+extends 'Code::TidyAll::Plugin';
+
+sub validate_file
+{
+    my ( $self, $fn ) = @_;
+    my $cmd = shell_quote( 'flake8', $fn );
+    if (`$cmd`)
+    {
+        die 'not valid';
+    }
+    return;
+}
+
+1;
+
+__END__
+
+=head1 COPYRIGHT & LICENSE
+
+Copyright 2018 by Shlomi Fish
+
+This program is distributed under the MIT / Expat License:
+L<http://www.opensource.org/licenses/mit-license.php>
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+=cut
diff --git a/tests/style/py-flake8.t b/tests/style/py-flake8.t
deleted file mode 100644
index 5bca436e..00000000
--- a/tests/style/py-flake8.t
+++ /dev/null
@@ -1,62 +0,0 @@
-#!/usr/bin/perl
-
-use strict;
-use warnings;
-
-use Test::More;
-use Test::Differences qw( eq_or_diff );
-
-use File::Find::Object ();
-use String::ShellQuote qw/ shell_quote /;
-
-if ( $^O =~ /\AMSWin/ )
-{
-    plan skip_all => "command line exceeded on ms windows.";
-}
-else
-{
-    plan tests => 1;
-}
-
-my %skip = (
-    map { $_ => 1 }
-        qw(
-        )
-);
-
-my $tree = File::Find::Object->new( {}, '.' );
-my @filenames;
-while ( my $r = $tree->next_obj )
-{
-    my $fn = $r->path;
-    if ( $fn eq '.git' or $fn eq 'tests/individually-importing' )
-    {
-        $tree->prune;
-    }
-    elsif ( $fn =~ /\.py\z/ and !exists( $skip{$fn} ) )
-    {
-        push @filenames, $fn;
-    }
-}
-
-my $cmd = shell_quote( 'flake8', @filenames );
-
-# diag("<$cmd>");
-
-# TEST
-eq_or_diff( scalar(`$cmd`), '', "flake8 is happy with the code." );
-
-__END__
-
-=head1 COPYRIGHT AND LICENSE
-
-This file is part of Freecell Solver. It is subject to the license terms in
-the COPYING.txt file found in the top-level directory of this distribution
-and at http://fc-solve.shlomifish.org/docs/distro/COPYING.html . No part of
-Freecell Solver, including this file, may be copied, modified, propagated,
-or distributed except according to the terms contained in the COPYING file.
-
-Copyright (c) 2016 Shlomi Fish
-
-=cut
-