diff --git a/nodeaccess.module b/nodeaccess.module
index 1b33402..814329b 100644
--- a/nodeaccess.module
+++ b/nodeaccess.module
@@ -692,14 +692,16 @@ function nodeaccess_node_update($node) {
   if (module_exists('user_reference')) {
     $fields = variable_get('nodeaccess_' . $node->type . '_user_reference', array());
     foreach (array_keys($fields) as $field_name) {
-      if (isset($node->$field_name)) {
-        $old_node = node_load($node->nid);
-        // Delete the old user as it's changed.
-        if ($node->$field_name != $old_node->$field_name) {
-          nodeaccess_delete_user_reference($old_node);
-          nodeaccess_insert_user_reference($node);
+      if ($fields[$field_name]['enabled']) {
+        if (isset($node->$field_name)) {
+          $old_node = node_load($node->nid);
+          // Delete the old user as it's changed.
+          if ($node->$field_name != $old_node->$field_name) {
+            nodeaccess_delete_user_reference($old_node);
+            nodeaccess_insert_user_reference($node);
+          }
+          break;
         }
-        break;
       }
     }
   }