diff --git a/kraken/serialization.py b/kraken/serialization.py
index fb2b8ef69..cb335a71b 100644
--- a/kraken/serialization.py
+++ b/kraken/serialization.py
@@ -163,7 +163,7 @@ def serialize(results: 'Segmentation',
 
         # set field to indicate the availability of baseline segmentation in
         # addition to bounding boxes
-        line = {'index': idx,
+        line = {'id': record.id,
                 'bbox': max_bbox([record.boundary]) if record.type == 'baselines' else record.bbox,
                 'cuts': record.cuts,
                 'confidences': record.confidences,
diff --git a/kraken/templates/alto b/kraken/templates/alto
index f018d2f5b..b3ab3fc4b 100644
--- a/kraken/templates/alto
+++ b/kraken/templates/alto
@@ -3,7 +3,7 @@
               'postprocessing': 'postOperation'}
 %}
 {%+ macro render_line(page, line) +%}
-                    <TextLine ID="line_{{ line.index }}" HPOS="{{ line.bbox[0] }}" VPOS="{{ line.bbox[1] }}" WIDTH="{{ line.bbox[2] - line.bbox[0] }}" HEIGHT="{{ line.bbox[3] - line.bbox[1] }}" {% if line.baseline %}BASELINE="{{ line.baseline|sum(start=[])|join(' ') }}"{% endif %} {% if line.tags %}TAGREFS="{% for type in page.line_types %}{% if type[0] in line.tags and line.tags["type[0]"] == type[1] %}LINE_TYPE_{{ loop.index }}{% endif %}{% endfor %}"{% endif %}>
+                    <TextLine ID="{{ line.id }}" HPOS="{{ line.bbox[0] }}" VPOS="{{ line.bbox[1] }}" WIDTH="{{ line.bbox[2] - line.bbox[0] }}" HEIGHT="{{ line.bbox[3] - line.bbox[1] }}" {% if line.baseline %}BASELINE="{{ line.baseline|sum(start=[])|join(' ') }}"{% endif %} {% if line.tags %}TAGREFS="{% for type in page.line_types %}{% if type[0] in line.tags and line.tags[type[0]] == type[1] %}LINE_TYPE_{{ loop.index }}{% endif %}{% endfor %}"{% endif %}>
                         {% if line.boundary %}
                         <Shape>
                             <Polygon POINTS="{{ line.boundary|sum(start=[])|join(' ') }}"/>
@@ -107,7 +107,7 @@
                 {% if loop.previtem and loop.previtem.type == 'line' %}
                 </TextBlock>
                 {% endif %}
-                <TextBlock ID="block_{{ entity.index }}" HPOS="{{ entity.bbox[0] }}" VPOS="{{ entity.bbox[1] }}" WIDTH="{{ entity.bbox[2] - entity.bbox[0] }}" HEIGHT="{{ entity.bbox[3] - entity.bbox[1] }}" {% for type in page.region_types %}{% if type == entity.region_type %}TAGREFS="REGION_TYPE_{{ loop.index }}"{% endif %}{% endfor %}>
+                <TextBlock ID="{{ entity.id }}" HPOS="{{ entity.bbox[0] }}" VPOS="{{ entity.bbox[1] }}" WIDTH="{{ entity.bbox[2] - entity.bbox[0] }}" HEIGHT="{{ entity.bbox[3] - entity.bbox[1] }}" {% for type in page.region_types %}{% if type in entity.tags.values() %}TAGREFS="REGION_TYPE_{{ loop.index }}"{% endif %}{% endfor %}>
                     <Shape>
                         <Polygon POINTS="{{ entity.boundary|sum(start=[])|join(' ') }}"/>
                     </Shape>
diff --git a/kraken/templates/pagexml b/kraken/templates/pagexml
index 6274eaf64..daea1ac00 100644
--- a/kraken/templates/pagexml
+++ b/kraken/templates/pagexml
@@ -1,5 +1,5 @@
 {%+ macro render_line(line) +%}
-            <TextLine id="line_{{ line.index }}">
+            <TextLine id="{{ line.id }}">
                 {% if line.boundary %}
                 <Coords points="{% for point in line.boundary %}{{ point|join(',') }}{% if not loop.last %} {% endif %}{% endfor %}"/>
                 {% endif %}
@@ -38,7 +38,7 @@
         {% if loop.previtem and loop.previtem.type == 'line' %}
         </TextRegion>
         {% endif %}
-        <TextRegion id="block_{{ entity.index }}" custom="structure {type:{{ entity.region_type }};}">
+        <TextRegion id="{{ entity.id }}" custom="structure {type:{{ entity.region_type }};}">
             <Coords points="{% for point in entity.boundary %}{{ point|join(',') }}{% if not loop.last %} {% endif %}{% endfor %}"/>
             {%- for line in entity.lines -%}
             {{ render_line(line) }}