diff --git a/js/app.js b/js/app.js
index a18b30f..53171d6 100644
--- a/js/app.js
+++ b/js/app.js
@@ -4713,7 +4713,17 @@ function soDirtyCheck() {
     if (btn) btn.style.display = isSoDirty() ? '' : 'none';
 }
 
+// Re-entrancy latch: a double-click on Save (or Enter+click) while the first
+// run awaits encryption/POST would fire a SECOND full save → duplicate entry.
+// Same async-race class as the sync-button guard.
+let soSaving = false;
 async function soSave() {
+    if (soSaving) return;
+    soSaving = true;
+    try { await soSaveInner(); } finally { soSaving = false; }
+}
+
+async function soSaveInner() {
     if (!soState) return;
     // Flush any uncommitted tag text — user may have typed in the chip
     // input without pressing Enter / comma before clicking Save.