diff --git a/umap/models.py b/umap/models.py
index 7bf8494f..e3e11e1c 100644
--- a/umap/models.py
+++ b/umap/models.py
@@ -194,10 +194,6 @@ class Map(NamedModel):
     objects = models.Manager()
     public = PublicManager()
 
-    @property
-    def unique_id(self):
-        return f"map_{self.pk}"
-
     @property
     def preview_settings(self):
         from .views import _urls_for_js
diff --git a/umap/templates/umap/map_table.html b/umap/templates/umap/map_table.html
index d5721d15..6da94810 100644
--- a/umap/templates/umap/map_table.html
+++ b/umap/templates/umap/map_table.html
@@ -13,31 +13,33 @@
   {% endif %}
   <tbody>
     {% for map_inst in maps %}
-      {{ map_inst.preview_settings|json_script:map_inst.unique_id }}
-      <tr>
-        <td>
-          <a href="{{ map_inst.get_absolute_url }}">{{ map_inst.name }}</a>
-          <button class="map-opener" data-map-id="{{ map_inst.unique_id }}">{% blocktrans %}Preview{% endblocktrans %}</button>
-          <dialog>
-            <form method="dialog">
-              <div id="{{ map_inst.unique_id }}_target" class="map_fragment"></div>
-              <p class="close-dialog">
-                <button type="submit">Close</button>
-              </p>
-            </form>
-          </dialog>
-        </td>
-        <td>{{ map_inst.get_share_status_display }} / {{ map_inst.get_edit_status_display }}</td>
-        <td>{{ map_inst.modified_at }}</td>
-        <td>
-          <a href="{{ map_inst.owner.get_url }}">{{ map_inst.owner }}</a>
-        </td>
-        <td>
-          <a href="{{ map_inst.get_absolute_url }}?share">{% translate "Share" %}</a> |
-          <a href="{{ map_inst.get_absolute_url }}?edit">{% translate "Edit" %}</a> |
-          <a href="{% url 'map_download' map_inst.pk %}">{% translate "Download" %}</a>
-        </td>
-      </tr>
+      {% with unique_id="map_"|addstr:map_inst.pk %}
+        {{ map_inst.preview_settings|json_script:unique_id }}
+        <tr>
+          <td>
+            <a href="{{ map_inst.get_absolute_url }}">{{ map_inst.name }}</a>
+            <button class="map-opener" data-map-id="{{ unique_id }}">{% blocktrans %}Preview{% endblocktrans %}</button>
+            <dialog>
+              <form method="dialog">
+                <div id="{{ unique_id }}_target" class="map_fragment"></div>
+                <p class="close-dialog">
+                  <button type="submit">Close</button>
+                </p>
+              </form>
+            </dialog>
+          </td>
+          <td>{{ map_inst.get_share_status_display }} / {{ map_inst.get_edit_status_display }}</td>
+          <td>{{ map_inst.modified_at }}</td>
+          <td>
+            <a href="{{ map_inst.owner.get_url }}">{{ map_inst.owner }}</a>
+          </td>
+          <td>
+            <a href="{{ map_inst.get_absolute_url }}?share">{% translate "Share" %}</a> |
+            <a href="{{ map_inst.get_absolute_url }}?edit">{% translate "Edit" %}</a> |
+            <a href="{% url 'map_download' map_inst.pk %}">{% translate "Download" %}</a>
+          </td>
+        </tr>
+      {% endwith %}
     {% endfor %}
   </tbody>
 </table>
diff --git a/umap/templatetags/umap_tags.py b/umap/templatetags/umap_tags.py
index 70728ffa..2349c579 100644
--- a/umap/templatetags/umap_tags.py
+++ b/umap/templatetags/umap_tags.py
@@ -60,3 +60,9 @@ def ipdb(what):
 
     ipdb.set_trace()
     return ""
+
+
+@register.filter
+def addstr(arg1, arg2):
+    # Necessity: https://stackoverflow.com/a/23783666
+    return str(arg1) + str(arg2)