diff --git a/xt/js_tidy.t b/xt/js_tidy.t
index 3cfedd1dca..d2deb04502 100755
--- a/xt/js_tidy.t
+++ b/xt/js_tidy.t
@@ -26,7 +26,7 @@ plan tests => scalar @js_files;
 
 foreach my $filepath (@js_files) {
     chomp $filepath;
-    my $tidy    = qx{yarn --silent run prettier $filepath};
+    my $tidy    = qx{perl misc/devel/tidy.pl --silent --no-write $filepath};
     my $content = read_file $filepath;
     ok( $content eq $tidy, "$filepath should be kept tidy" );
 }
diff --git a/xt/vue_tidy.t b/xt/vue_tidy.t
index 3b16c4b003..03ab503308 100755
--- a/xt/vue_tidy.t
+++ b/xt/vue_tidy.t
@@ -25,7 +25,7 @@ plan tests => scalar @vue_files;
 
 foreach my $filepath (@vue_files) {
     chomp $filepath;
-    my $tidy    = qx{yarn --silent run prettier $filepath};
+    my $tidy    = qx{perl misc/devel/tidy.pl --silent --no-write $filepath};
     my $content = read_file $filepath;
     ok( $content eq $tidy, "$filepath should be kept tidy" );
 }