diff --git a/CHANGELOG-v2.md b/CHANGELOG-v2.md
index 260f5391bc2..2a07cd72f92 100644
--- a/CHANGELOG-v2.md
+++ b/CHANGELOG-v2.md
@@ -1,5 +1,10 @@
 # Release Notes for Craft CMS 2.x
 
+## Unreleased
+
+### Fixed
+- Fixed an error that occurred when saving a Single entry over Ajax. ([#2687](https://github.com/craftcms/cms/issues/2687))
+
 ## 2.6.3015 - 2018-04-06
 
 ### Changed
diff --git a/src/controllers/EntriesController.php b/src/controllers/EntriesController.php
index 71b83893dd9..ec3e8338099 100644
--- a/src/controllers/EntriesController.php
+++ b/src/controllers/EntriesController.php
@@ -472,7 +472,11 @@ public function actionSaveEntry()
 					$return['cpEditUrl'] = $entry->getCpEditUrl();
 				}
 
-				$return['authorUsername']      = $entry->getAuthor()->username;
+				if (($author = $entry->getAuthor()) !== null)
+				{
+					$return['authorUsername'] = $author->username;
+				}
+
 				$return['dateCreated'] = DateTimeHelper::toIso8601($entry->dateCreated);
 				$return['dateUpdated'] = DateTimeHelper::toIso8601($entry->dateUpdated);
 				$return['postDate']    = ($entry->postDate ? DateTimeHelper::toIso8601($entry->postDate) : null);