diff --git a/pages/object.php b/pages/object.php
index 467dcd02..76ff3dc0 100644
--- a/pages/object.php
+++ b/pages/object.php
@@ -414,7 +414,7 @@ class ObjectPage extends GenericPage
                     'id'        => 'contains',
                     'name'      => '$LANG.tab_contains',
                     'sort'      => ['-percent', 'name'],
-                    'extraCols' => $extraCols
+                    'extraCols' => array_unique($extraCols)
                 );
 
                 if ($hiddenCols)
diff --git a/pages/spell.php b/pages/spell.php
index 60701a64..2b0bfa8d 100644
--- a/pages/spell.php
+++ b/pages/spell.php
@@ -690,7 +690,7 @@ class SpellPage extends GenericPage
                 'name'       => '$LANG.tab_contains',
                 'id'         => 'contains',
                 'hiddenCols' => ['side', 'slot', 'source', 'reqlevel'],
-                'extraCols'  => $extraCols
+                'extraCols'  => array_unique($extraCols)
             )];
         }