diff --git a/web/pdf_scripting_manager.js b/web/pdf_scripting_manager.js
index 9da66880d..b8f2ed9f9 100644
--- a/web/pdf_scripting_manager.js
+++ b/web/pdf_scripting_manager.js
@@ -45,6 +45,8 @@ class PDFScriptingManager {
 
   #externalServices = null;
 
+  #objectIds = null;
+
   #pdfDocument = null;
 
   #pdfViewer = null;
@@ -104,6 +106,18 @@ class PDFScriptingManager {
     if (pdfDocument !== this.#pdfDocument) {
       return; // The document was closed while the data resolved.
     }
+
+    // Collect the ids of every field annotation, so that any sandbox message
+    // targeting an unknown id can be ignored.
+    if (objects) {
+      this.#objectIds = new Set();
+      for (const fields of Object.values(objects)) {
+        for (const { id } of fields) {
+          this.#objectIds.add(id);
+        }
+      }
+    }
+
     try {
       this.#scripting = this.#initScripting();
     } catch (error) {
@@ -368,6 +382,9 @@ class PDFScriptingManager {
 
     const ids = siblings ? [id, ...siblings] : [id];
     for (const elementId of ids) {
+      if (!this.#objectIds?.has(elementId)) {
+        continue;
+      }
       const element = document.querySelector(
         `[data-element-id="${elementId}"]`
       );
@@ -456,6 +473,8 @@ class PDFScriptingManager {
   }
 
   async #destroyScripting() {
+    this.#objectIds = null;
+
     if (!this.#scripting) {
       this.#pdfDocument = null;