diff --git a/wp-includes/category-template.php b/wp-includes/category-template.php
index 681ae6fa46..6218896d98 100644
--- a/wp-includes/category-template.php
+++ b/wp-includes/category-template.php
@@ -332,7 +332,7 @@ function category_description( $category = 0 ) {
 function wp_dropdown_categories( $args = '' ) {
 	$defaults = array(
 		'show_option_all' => '', 'show_option_none' => '',
-		'orderby' => 'ID', 'order' => 'ASC',
+		'orderby' => 'id', 'order' => 'ASC',
 		'show_last_update' => 0, 'show_count' => 0,
 		'hide_empty' => 1, 'child_of' => 0,
 		'exclude' => '', 'echo' => 1,
diff --git a/wp-includes/taxonomy.php b/wp-includes/taxonomy.php
index 3120faa866..3c5c1d75c9 100644
--- a/wp-includes/taxonomy.php
+++ b/wp-includes/taxonomy.php
@@ -671,17 +671,18 @@ function &get_terms($taxonomies, $args = '') {
 		return $cache;
 	}
 
-	if ( 'count' == $orderby )
+	$_orderby = strtolower($orderby);
+	if ( 'count' == $_orderby )
 		$orderby = 'tt.count';
-	else if ( 'name' == $orderby )
+	else if ( 'name' == $_orderby )
 		$orderby = 't.name';
-	else if ( 'slug' == $orderby )
+	else if ( 'slug' == $_orderby )
 		$orderby = 't.slug';
-	else if ( 'term_group' == $orderby )
+	else if ( 'term_group' == $_orderby )
 		$orderby = 't.term_group';
-	elseif ( empty($orderby) || 'id' == $orderby ) 
+	elseif ( empty($_orderby) || 'id' == $_orderby ) 
 		$orderby = 't.term_id';
-    
+
 	$orderby = apply_filters( 'get_terms_orderby', $orderby, $args );
 
 	$where = '';