diff --git a/templates/admin/metadata_backfill.html b/templates/admin/metadata_backfill.html
index 84459cd..41bd18e 100644
--- a/templates/admin/metadata_backfill.html
+++ b/templates/admin/metadata_backfill.html
@@ -275,7 +275,13 @@ async function _fetchTypeahead(input, fieldKind) {
         return;
     }
 
+    // Args go in data-* attributes (not inline onclick) to avoid the quote
+    // collision when location names contain characters JSON.stringify quotes
+    // (e.g. anything with spaces/punctuation — basically every real name).
+    // _esc() escapes for HTML attribute context (entities for <>&"), then
+    // the browser decodes them when reading the dataset value.
     dropdown.innerHTML = items.map((it, idx) => {
+        const cid = _esc(input.dataset.clusterId);
         if (it.kind === 'match') {
             const m = it.payload;
             const scoreBadge = m.score >= 0.99
@@ -291,16 +297,24 @@ async function _fetchTypeahead(input, fieldKind) {
             }
             const metaLine = meta.length ? `<div class="text-xs text-gray-500 dark:text-gray-400">${meta.join(' · ')}</div>` : '';
             return `<button type="button"
+                data-cid="${cid}"
+                data-field-kind="${fieldKind}"
+                data-entity-id="${_esc(m.id)}"
+                data-entity-name="${_esc(m.name)}"
                 onmousedown="event.preventDefault()"
-                onclick="onTypeaheadPick(event, '${_esc(input.dataset.clusterId)}', '${fieldKind}', '${_esc(m.id)}', ${JSON.stringify(m.name)})"
+                onclick="_typeaheadPickFromButton(this)"
                 class="w-full text-left px-3 py-2 hover:bg-gray-50 dark:hover:bg-slate-700 border-b border-gray-100 dark:border-gray-700 last:border-b-0">
                 <div class="text-sm font-medium text-gray-900 dark:text-white">${_esc(m.name)}${scoreBadge}</div>
                 ${metaLine}
             </button>`;
         }
         return `<button type="button"
+            data-cid="${cid}"
+            data-field-kind="${fieldKind}"
+            data-entity-id=""
+            data-entity-name="${_esc(it.name)}"
             onmousedown="event.preventDefault()"
-            onclick="onTypeaheadPick(event, '${_esc(input.dataset.clusterId)}', '${fieldKind}', '', ${JSON.stringify(it.name)})"
+            onclick="_typeaheadPickFromButton(this)"
             class="w-full text-left px-3 py-2 hover:bg-orange-50 dark:hover:bg-orange-900/20 border-t border-gray-200 dark:border-gray-700 text-seismo-orange font-medium text-sm">
             + ${_esc(it.label)}
         </button>`;
@@ -308,6 +322,19 @@ async function _fetchTypeahead(input, fieldKind) {
     dropdown.classList.remove('hidden');
 }
 
+// Trampoline — reads the click target's data-* attributes and forwards
+// to onTypeaheadPick.  Keeps the inline onclick attribute free of any
+// string interpolation that could collide with HTML quoting.
+function _typeaheadPickFromButton(btn) {
+    onTypeaheadPick(
+        null,
+        btn.dataset.cid,
+        btn.dataset.fieldKind,
+        btn.dataset.entityId || '',
+        btn.dataset.entityName || ''
+    );
+}
+
 function onTypeaheadPick(event, clusterId, fieldKind, entityId, name) {
     // entityId is empty string for "create new", or a UUID for matched existing.
     const inputs = document.querySelectorAll(`input[data-cluster-id="${clusterId}"]`);