diff --git a/scratch/perl/text-piecetable/lib/Tree/BinaryFP.pm b/scratch/perl/text-piecetable/lib/Tree/BinaryFP.pm
index 450c5e3..9ed9227 100644
--- a/scratch/perl/text-piecetable/lib/Tree/BinaryFP.pm
+++ b/scratch/perl/text-piecetable/lib/Tree/BinaryFP.pm
@@ -18,8 +18,8 @@ sub reverse {
     my $self = shift;
     return $self->new({
         %$self,
-        left => $self->right,
-        right => $self->left,
+        left => $self->right->reverse,
+        right => $self->left->reverse,
     });
 }
 sub mk_node {
diff --git a/scratch/perl/text-piecetable/t/04-tree-fp.t b/scratch/perl/text-piecetable/t/04-tree-fp.t
index 6688456..f62a4bf 100644
--- a/scratch/perl/text-piecetable/t/04-tree-fp.t
+++ b/scratch/perl/text-piecetable/t/04-tree-fp.t
@@ -54,6 +54,9 @@ sub test_match {
 test_match( $node, 0, e(d,f), 'e(d,f)' );
 my ($e, $f, $d) = 
 test_match( $node, 1, e(f,d), 'e(f,d)' );
+test_match( $node, 1, e(f,any), 'e(f,any)' );
+
+test_match( $node, 1, e(any,f)->reverse, 'e(any,f)->reverse' );
 test_match( $node, 1, e(d,f)->reverse, 'e(d,f)->reverse' );
 test_match( $node, 1, e(undef,d), 'e(undef,d)' );
 test_match( $node, 1, e(f,undef), 'e(f,undef)' );