diff --git a/src/codegen.inc.php b/src/codegen.inc.php
index 33c498a..dc57829 100644
--- a/src/codegen.inc.php
+++ b/src/codegen.inc.php
@@ -82,6 +82,26 @@ function _add_twig_support(\Twig\Environment $twig)
         return $v;
     }
   ));
+  $twig->addFunction(new \Twig\TwigFunction('field_index', 
+    function(\mtgMetaStruct $s, string $f): int
+    {
+      $idx = get_field_index($s, $f);
+      if($idx == -1)
+      {
+        throw new Exception("field `$f` not found in `{$s->getName()}`");
+      }
+
+      return $idx;
+    }
+  ));
+  $twig->addFunction(new \Twig\TwigFunction('find_struct', 
+    function(string $name) use ($twig): \mtgMetaStruct
+    {
+      $meta = $twig->getGlobals()['meta'];
+      $unit = $meta->findUnit($name);
+      return $unit->object;
+    }
+  ));
   $twig->addFilter(new \Twig\TwigFilter('cs_type', 
     function($type) 
     {
@@ -619,3 +639,16 @@ function get_all_declarable_accessor_interfaces(\mtgMetaInfo $info)
   return $all;
 }
 
+function get_field_index(\mtgMetaStruct $struct, string $field_name): int
+{
+  $idx = -1;
+  foreach($struct->getFields() as $field)
+  {
+    $idx++;
+    if($field->getName() == $field_name)
+    {
+      return $idx;
+    }
+  }
+  return -1;
+}
diff --git a/tpl/macro.twig b/tpl/macro.twig
index e44a9a9..64d8d3c 100644
--- a/tpl/macro.twig
+++ b/tpl/macro.twig
@@ -395,7 +395,7 @@ public class {{o.name}} : IRpc
       {% set field_idx = field_idx + 1 %}
       
       {%- if not has_token(f, 'nodiff') -%}
-      {{_self.field_diff(f, field_idx)}}
+      {{_self.field_diff(f, field_idx, o)}}
       {%- endif -%}
     {% endfor %}
 
@@ -561,7 +561,7 @@ public class {{o.name}} : IRpc
 
 {% endmacro %}
 
-{%- macro field_diff(f, field_idx) -%}
+{%- macro field_diff(f, field_idx, o) -%}
 
 {% if f.type is instanceof('\\mtgMetaStruct') %}
   {%- if not has_token(f.type, 'POD') -%}
@@ -594,7 +594,7 @@ public class {{o.name}} : IRpc
     if(diff != null) 
       MetaIO.SetFieldDirty(ref diff.fields_mask, {{field_idx}});
     if(removed != null && removed.{{f.name}}.Count > 0)
-      MetaIO.SetFieldDirty(ref removed.fields_mask, {{field_idx}});
+      MetaIO.SetFieldDirty(ref removed.fields_mask, {{ field_index(find_struct(o.name ~ 'RemovedIds'), f.name) }});
   }
 {% elseif f.type is instanceof('\\mtgBuiltinType') %}
   if(diff != null)