diff --git a/public_html/js/Presenters/PostEditPresenter.js b/public_html/js/Presenters/PostEditPresenter.js
index ff68189e..de139797 100644
--- a/public_html/js/Presenters/PostEditPresenter.js
+++ b/public_html/js/Presenters/PostEditPresenter.js
@@ -109,7 +109,7 @@ App.Presenters.PostEditPresenter = function(
     function editPost() {
         var $form = $target.find('form');
         var formData = new FormData();
-        formData.append('seenEditTime', post.lastEditTime);
+        formData.append('lastEditTime', post.lastEditTime);
 
         if (privileges.canChangeContent && postContent) {
             formData.append('content', postContent);
diff --git a/src/FormData/PostEditFormData.php b/src/FormData/PostEditFormData.php
index c4a68738..528f42ef 100644
--- a/src/FormData/PostEditFormData.php
+++ b/src/FormData/PostEditFormData.php
@@ -14,7 +14,7 @@ class PostEditFormData implements IValidatable
     public $relations;
     public $flags;
 
-    public $seenEditTime;
+    public $lastEditTime;
 
     public function __construct($inputReader = null)
     {
@@ -29,7 +29,7 @@ class PostEditFormData implements IValidatable
             $this->tags = preg_split('/[\s+]/', $inputReader->tags);
             if ($inputReader->relations !== null)
                 $this->relations = array_filter(preg_split('/[\s+]/', $inputReader->relations));
-            $this->seenEditTime = $inputReader->seenEditTime;
+            $this->lastEditTime = $inputReader->lastEditTime;
             $this->flags = new \StdClass;
             $this->flags->loop = !empty($inputReader->loop);
         }
diff --git a/src/Services/PostService.php b/src/Services/PostService.php
index 3a6d211e..6141bd2b 100644
--- a/src/Services/PostService.php
+++ b/src/Services/PostService.php
@@ -140,7 +140,10 @@ class PostService
         {
             $this->validator->validate($formData);
 
-            if ($post->getLastEditTime() !== $formData->seenEditTime)
+            if (!$formData->lastEditTime)
+                throw new \DomainException('Last edit time was not provided; cannot edit post.');
+
+            if ($post->getLastEditTime() !== $formData->lastEditTime)
                 throw new \DomainException('Someone has already edited this post in the meantime.');
 
             $post->setLastEditTime($this->timeService->getCurrentTime());