diff --git a/.gitignore b/.gitignore
index 65ad0e8..7254a62 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ lab
 .envrc
 *.orig
 *.tdy
+*.ERR
diff --git a/xt/perltidy.t b/xt/perltidy.t
index f2cad2f..0f13291 100644
--- a/xt/perltidy.t
+++ b/xt/perltidy.t
@@ -17,7 +17,9 @@ if ($on_target) {
 else {
     my @files =
       $git->diff( { name_only => 1, diff_filter => 'ACMR' }, $target_branch );
-    ok Test::PerlTidy::is_file_tidy($_), $_ for @files;
+    ok Test::PerlTidy::is_file_tidy($_), $_
+      for grep { /\.(pl|pm|pod|t)$/ } @files;
+
 }
 
 done_testing;