diff --git a/src/applications/legalpad/xaction/LegalpadDocumentRequireSignatureTransaction.php b/src/applications/legalpad/xaction/LegalpadDocumentRequireSignatureTransaction.php
index 3819f38a70..9932baab80 100644
--- a/src/applications/legalpad/xaction/LegalpadDocumentRequireSignatureTransaction.php
+++ b/src/applications/legalpad/xaction/LegalpadDocumentRequireSignatureTransaction.php
@@ -1,72 +1,83 @@
 <?php
 
 final class LegalpadDocumentRequireSignatureTransaction
   extends LegalpadDocumentTransactionType {
 
   const TRANSACTIONTYPE = 'legalpad:require-signature';
 
   public function generateOldValue($object) {
     return (int)$object->getRequireSignature();
   }
 
   public function applyInternalEffects($object, $value) {
     $object->setRequireSignature((int)$value);
   }
 
   public function applyExternalEffects($object, $value) {
     if ($value) {
       $session = new PhabricatorAuthSession();
       queryfx(
         $session->establishConnection('w'),
         'UPDATE %T SET signedLegalpadDocuments = 0',
         $session->getTableName());
     }
   }
 
   public function getTitle() {
     $new = $this->getNewValue();
 
     if ($new) {
       return pht(
         '%s set the document to require signatures.',
         $this->renderAuthor());
     } else {
       return pht(
         '%s set the document to not require signatures.',
         $this->renderAuthor());
     }
   }
 
   public function getTitleForFeed() {
     $new = $this->getNewValue();
     if ($new) {
       return pht(
         '%s set the document %s to require signatures.',
         $this->renderAuthor(),
         $this->renderObject());
     } else {
       return pht(
         '%s set the document %s to not require signatures.',
         $this->renderAuthor(),
         $this->renderObject());
     }
   }
 
   public function validateTransactions($object, array $xactions) {
     $errors = array();
 
-    $is_admin = $this->getActor()->getIsAdmin();
+    $old = (bool)$object->getRequireSignature();
+    foreach ($xactions as $xaction) {
+      $new = (bool)$xaction->getNewValue();
 
-    if (!$is_admin) {
-      $errors[] = $this->newInvalidError(
-        pht('Only admins may require signature.'));
+      if ($old === $new) {
+        continue;
+      }
+
+      $is_admin = $this->getActor()->getIsAdmin();
+      if (!$is_admin) {
+        $errors[] = $this->newInvalidError(
+          pht(
+            'Only administrators may change whether a document '.
+            'requires a signature.'),
+          $xaction);
+      }
     }
 
     return $errors;
   }
 
   public function getIcon() {
     return 'fa-pencil-square';
   }
 
 }