diff --git a/web/lindat-service/run.php b/web/lindat-service/run.php
index 3026e6a..376ee42 100644
--- a/web/lindat-service/run.php
+++ b/web/lindat-service/run.php
@@ -124,6 +124,7 @@ function showTree() {
     var tree_desc = [];
     var tree_nodes = [];
 
+    var is_pdtc = output_file_content.indexOf("\n# udpipe_model = czech-pdtc") >= 0
     var lines = output_file_content.split(/\r?\n/);
     lines.push('');
     for (var i in lines) {
@@ -134,12 +135,16 @@ function showTree() {
 
         if (tree_desc.length) tree_desc.push([' ', 'space']);
         tree_desc.push([parts[1], 'w'+parts[0]]);
-
-        if (!tree_nodes.length) tree_nodes.push({id:'w0', ord:0, parent:null, data:{id:"0",form:"<root>"}, labels:['<root>','','']});
+        if (!tree_nodes.length) {
+          if (is_pdtc)
+            tree_nodes.push({id:'w0', ord:0, parent:null, data:{id:"0",deprel:"AuxS"}, labels:['#{#00008b}AuxS','','']});
+          else
+            tree_nodes.push({id:'w0', ord:0, parent:null, data:{id:"0",form:"<root>"}, labels:['<root>','','']});
+        }
         tree_nodes.push({id:'w'+parts[0], ord:tree_nodes.length, parent:parts[6]!==""?'w'+parts[6]:null, data:{
           id:parts[0], form:parts[1], lemma:parts[2], upostag:parts[3], xpostag:parts[4],
           feats:parts[5], head:parts[6], deprel:parts[7], deps:parts[8], misc:parts[9]
-        }, labels:[parts[1], '#{#00008b}'+parts[7], '#{#004048}'+parts[3]]});
+        }, labels:[parts[1], '#{#00008b}'+parts[7], '#{#004048}'+(is_pdtc ? parts[4].replace(/-*$/, "") : parts[3])]});
       } else if (tree_nodes.length) {
         var last_child = [];
         for (var i = 1; i < tree_nodes.length; i++) {