diff --git a/classes/Managed_DataObject.php b/classes/Managed_DataObject.php
index e645b5aec9..8d9bca11b0 100644
--- a/classes/Managed_DataObject.php
+++ b/classes/Managed_DataObject.php
@@ -334,7 +334,7 @@ abstract class Managed_DataObject extends Memcached_DataObject
         $object = new $classname();
         foreach ($pkey as $col) {
             if (!array_key_exists($col, $vals)) {
-                throw new ServerException("Missing primary key column '{$col}'");
+                throw new ServerException("Missing primary key column '{$col}' for ".get_called_class()." among provided keys: ".implode(',', array_keys($vals)));
             } elseif (is_null($vals[$col])) {
                 throw new ServerException("NULL values not allowed in getByPK for column '{$col}'");
             }
diff --git a/plugins/ActivityModeration/classes/Deleted_notice.php b/plugins/ActivityModeration/classes/Deleted_notice.php
index 3c6adeb802..9a0a65c6b2 100644
--- a/plugins/ActivityModeration/classes/Deleted_notice.php
+++ b/plugins/ActivityModeration/classes/Deleted_notice.php
@@ -99,7 +99,7 @@ class Deleted_notice extends Managed_DataObject
     static public function fromStored(Notice $stored)
     {
         $class = get_called_class();
-        return self::getByPK(array('uri', $stored->getUri()));
+        return self::getByPK(array('uri' => $stored->getUri()));
     }
 
     // The one who deleted the notice, not the notice's author
@@ -125,7 +125,7 @@ class Deleted_notice extends Managed_DataObject
     {
         $uri = $this->getUri();
         if (!isset($this->_stored[$uri])) {
-            $this->_stored[$uri] = Notice::getByPK('uri', $uri);
+            $this->_stored[$uri] = Notice::getByPK(array('uri' => $uri));
         }
         return $this->_stored[$uri];
     }
diff --git a/plugins/Bookmark/BookmarkPlugin.php b/plugins/Bookmark/BookmarkPlugin.php
index 6b0c07b6a5..e0f30700ae 100644
--- a/plugins/Bookmark/BookmarkPlugin.php
+++ b/plugins/Bookmark/BookmarkPlugin.php
@@ -479,7 +479,7 @@ class BookmarkPlugin extends MicroAppPlugin
     {
         assert($obj->type == ActivityObject::BOOKMARK);
 
-        $bm = Bookmark::getByPK(array('uri', $obj->id));
+        $bm = Bookmark::getByPK(array('uri' => $obj->id));
 
         $out['displayName'] = $bm->getTitle();
         $out['targetUrl']   = $bm->getUrl();
diff --git a/plugins/Bookmark/classes/Bookmark.php b/plugins/Bookmark/classes/Bookmark.php
index e92fd33449..cdbdf526ca 100644
--- a/plugins/Bookmark/classes/Bookmark.php
+++ b/plugins/Bookmark/classes/Bookmark.php
@@ -69,9 +69,9 @@ class Bookmark extends Managed_DataObject
                 'description' => array('type' => 'text'),
                 'created' => array('type' => 'datetime', 'not null' => true),
             ),
-            'primary key' => array('id'),
+            'primary key' => array('uri'),
             'unique keys' => array(
-                'bookmark_uri_key' => array('uri'),
+                'bookmark_id_key' => array('id'),
             ),
             'foreign keys' => array(
                 'bookmark_profile_id_fkey' => array('profile', array('profile_id' => 'id')),
@@ -94,8 +94,7 @@ class Bookmark extends Managed_DataObject
      */
     static public function fromStored(Notice $stored)
     {
-        $class = get_called_class();
-        return self::getByPK(array('uri', $stored->getUri()));
+        return self::getByPK(array('uri' => $stored->getUri()));
     }
 
     /**