diff --git a/Tests/dblayerooComplet.php b/Tests/dblayerooComplet.php
index c908212..d6345e4 100644
--- a/Tests/dblayerooComplet.php
+++ b/Tests/dblayerooComplet.php
@@ -829,4 +829,29 @@ class test_dblayeroo_{ENGINE} extends PHPUnit_Framework_TestCase
                        $res);
   }
 
+  public function test_update5 ()
+  {
+    // Manage to update the non unique fields
+    // the "where" column is not unique, so it allow to have twice the same
+    // value
+    $db1 = $this->db1 ();
+    $res = $db1->update()
+               ->setValues(array ("where"=>"where2"))
+               ->execute ();
+    $db1->disconnect ();
+    $this->assertSame (2, $res);
+  }
+
+  public function test_update6 ()
+  {
+    // Manage to update the primary / unique fields
+    // There is 2 lines in the DB, so the unique key "group" can not be updated
+    // with the same value twice (the result can not be unique)
+    $db1 = $this->db1 ();
+    $this->setExpectedException ("Exception");
+    $res = $db1->update()
+               ->setValues(array ("group"=>"group3"))
+               ->execute ();
+    $db1->disconnect ();
+  }
 }
diff --git a/dblayeroo.php b/dblayeroo.php
index 452c222..c0b13ef 100644
--- a/dblayeroo.php
+++ b/dblayeroo.php
@@ -2539,36 +2539,48 @@ class dblayeroo
     if (! in_array ($this->primary, $uniques))
       $uniques = array_merge (array ($this->primary), $uniques);
     $setValues = $values;
-    if (! array_key_exists ($this->primary, $setValues))
-      $setValues[$this->primary] = null;
+    $foundImpactedColumns = 0;
     foreach ($uniques as $k=>$columns)
     {
-      if ($update !== false && ! isset ($resUpdate))
+      if ($update)
       {
         // Can not update multiple UNIQUE rows with the same value
-        $this->debugLog ("CLONE because of update");
-        $objTmp = clone $this;
-        $objTmp->debugDepth++;
-        $objTmp->clearRequest ();
-        $objTmp->Select ();
-        $objTmp->displayAdd ($this->primary);
-        $objTmp->displayAdd ($columns);
-        $objTmp->whereValues = $this->whereValues;
-        $objTmp->whereExpression = $this->whereExpression;
-        $objTmp->limitLines (3);
-        $resUpdate = $objTmp->execute ();
-        unset ($objTmp);
-/*        if (count ($resUpdate) > 1)
-          $this->DBException (sprintf (dgettext ("domframework",
-            "Can't update multiple rows with unique value"), $columns));
-*/
-        if (count ($resUpdate) === 0)
+        $cols = explode (",", $columns);
+        foreach ($cols as $col)
+        {
+          if (!key_exists ($col, $setValues))
+            continue;
+          // One column to set is a unique column : check if the where clause
+          // is filtering more than one entry. If there is more than one
+          // entry, generate an exception
+          $this->debugLog ("CLONE because of update");
+          $objTmp = clone $this;
+          $objTmp->debugDepth++;
+          $objTmp->clearRequest ();
+          $objTmp->Select ();
+          $objTmp->displayAdd ($this->primary);
+          $objTmp->displayAdd ($columns);
+          $objTmp->whereValues = $this->whereValues;
+          $objTmp->whereExpression = $this->whereExpression;
+          $objTmp->limitLines (3);
+          $resUpdate = $objTmp->execute ();
+          unset ($objTmp);
+          if (count ($resUpdate) > 1)
+            $this->DBException (sprintf (dgettext ("domframework",
+              "Can't update multiple rows with unique value on col '%s'"),
+              $col));
+          elseif (count ($resUpdate) === 1)
+            $foundImpactedColumns++;
+        }
+        if ($foundImpactedColumns === 0)
         {
           // There is no row available with the WHERE clause provided
           // Skip all the UNIQUE tests as there will not have any modification
           break;
         }
       }
+      if (! array_key_exists ($this->primary, $setValues))
+        $setValues[$this->primary] = null;
 
       $this->debugLog ("CLONE to check primary and unique constraint");
       $objTmp = clone $this;