diff --git a/field_permissions.module b/field_permissions.module
index 9bef90b..b124099 100644
--- a/field_permissions.module
+++ b/field_permissions.module
@@ -171,14 +171,25 @@ function _field_permissions_field_view_access($field_name, $obj_type, $object, $
  * Implementation of hook_field_access('edit').
  */
 function _field_permissions_field_edit_access($field_name, $obj_type, $object, $account) {
-  // Check if the object is already created.
-  // @TODO: There is an exception warning that is issued here, hence the @. We
-  // should remove the @ when the Drupal core bug is fixed. You can find the
-  // bug here: http://drupal.org/node/1301522
-  list($id, $vid, $bundle) = @entity_extract_ids($obj_type, $object);
-
-  // Check if user has access to edit this field on object creation.
-  if (!isset($id)) {
+  // If this is a new object, check if the user has access to edit the field on
+  // object creation.
+  if (!isset($object)) {
+    // If the object doesn't exist, we assume it's new.
+    $is_new = TRUE;
+  }
+  else {
+    // If the object does exist, we check its ID to see if it's new. Using
+    // empty() rather than !isset() is important here, to deal with the case of
+    // entities that store "0" as their ID while the final entity is in the
+    // process of being created (user accounts are a good example of this).
+    //
+    // @TODO: There is an exception warning that is issued here, hence the @.
+    // We should remove the @ when the Drupal core bug is fixed. You can find
+    // the bug here: http://drupal.org/node/1301522
+    list($id, $vid, $bundle) = @entity_extract_ids($obj_type, $object);
+    $is_new = empty($id);
+  }
+  if ($is_new) {
     return user_access('create ' . $field_name, $account);
   }
 
diff --git a/field_permissions.test b/field_permissions.test
index 9253581..201fa46 100644
--- a/field_permissions.test
+++ b/field_permissions.test
@@ -23,7 +23,7 @@ class FieldPermissionsTestCase extends DrupalWebTestCase {
   }
 
   function setUp() {
-    parent::setUp('field_permissions');
+    parent::setUp('field_ui', 'field_permissions');
 
     // Create test user.
     $admin_permissions = array('access content', 'administer nodes', 'bypass node access', 'administer content types', 'administer taxonomy', 'administer permissions', 'create page content');
@@ -33,6 +33,7 @@ class FieldPermissionsTestCase extends DrupalWebTestCase {
     $this->limited_rid = array_pop($all_rids);
 
     $admin_permissions[] = 'administer field permissions';
+    $admin_permissions[] = 'administer users';
     $this->admin_user = $this->drupalCreateUser($admin_permissions);
     $all_rids = array_keys($this->admin_user->roles);
     sort($all_rids);
@@ -263,6 +264,39 @@ class FieldPermissionsTestCase extends DrupalWebTestCase {
     $this->assertText($field_info['value']);
   }
 
+  function testUserFields() {
+    // Create a field attached to users and make it appear on the user
+    // registration form with (default) custom permissions.
+    $this->drupalLogin($this->admin_user);
+    $label = 'Field attached to users';
+    $edit = array(
+      'fields[_add_new_field][label]' => $label,
+      'fields[_add_new_field][field_name]' => 'attached_to_users',
+      'fields[_add_new_field][type]' => 'text',
+      'fields[_add_new_field][widget_type]' => 'text_textfield',
+    );
+    $this->drupalPost('admin/config/people/accounts/fields',  $edit, t('Save'));
+    $this->drupalPost(NULL, array(), t('Save field settings'));
+    $edit = array(
+      'field[field_permissions][type]' => 2,
+      'instance[settings][user_register_form]' => TRUE,
+    );
+    $this->drupalPost(NULL, $edit, t('Save settings'));
+
+    // Log out, go to the registration form and make sure the field appears
+    // there for anonymous users.
+    $this->drupalLogout();
+    $this->drupalGet('user/register');
+    $this->assertText($label);
+
+    // Log in and make sure the user does not have access to edit the field
+    // (i.e., there are only default permissions to create it).
+    $this->drupalLogin($this->limited_user);
+    $this->drupalGet('user/' . $this->limited_user->uid . '/edit');
+    $this->assertResponse(200);
+    $this->assertNoText($label);
+  }
+
   /**
    * Asserts that a user account has a permission.
    */