diff --git a/Tests/dblayerooComplet.php b/Tests/dblayerooComplet.php
index 716fd44..a1f3057 100644
--- a/Tests/dblayerooComplet.php
+++ b/Tests/dblayerooComplet.php
@@ -957,4 +957,21 @@ class test_dblayeroo_{ENGINE} extends PHPUnit_Framework_TestCase
     $this->assertSame (array (0=>array ("ALIAS"=>"where2")),
                        $res);
   }
+
+  public function test_orderAdd_alias1 ()
+  {
+    $tbl2 = $this->tbl2 ();
+    $res = $tbl2->select ()
+                ->displayAdd ("uid", "max")
+                ->orderAdd ("max","ASC")
+                ->execute ();
+    $tbl2->disconnect ();
+    $this->assertSame (array (
+      array ('max' => 1),
+      array ('max' => 4),
+      array ('max' => 5),
+      array ('max' => 6),
+    ), $res);
+  }
+
 }
diff --git a/dblayeroo.php b/dblayeroo.php
index 98f31da..cf2698c 100644
--- a/dblayeroo.php
+++ b/dblayeroo.php
@@ -2063,9 +2063,11 @@ class dblayeroo
     if (! in_array ($sort, array ("ASC", "DESC", "NATASC", "NATDESC")))
       $this->DBException (
         "Invalid sort provided (not ASC nor DESC nor NATASC nor NATDESC)");
-    if (! array_key_exists ($field, $this->fields))
+    if (! array_key_exists ($field, $this->fields) &&
+        ! in_array ($field, $this->displayAlias))
       $this->DBException (sprintf (
-        "Invalid field to orderAdd '%s' : not defined in table", $field));
+        "Invalid field to orderAdd '%s' : not defined in table nor in alias",
+        $field));
     $plus = "";
     if (substr ($sort, 0, 3) === "NAT")
     {