diff --git a/modules/node/node.pages.inc b/modules/node/node.pages.inc
index 32f53f52276b6da9667d6487a5e7002526beae1d..fb1a37a11b6d2342d3d5e3818a480e2d506a77a1 100644
--- a/modules/node/node.pages.inc
+++ b/modules/node/node.pages.inc
@@ -107,7 +107,9 @@ function node_form(&$form_state, $node) {
       $node->$key = NULL;
     }
   }
-  node_object_prepare($node);
+  if (!isset($form_state['node_preview'])) {
+    node_object_prepare($node);
+  }
 
   // Set the id of the top-level form tag
   $form['#id'] = 'node-form';