diff --git a/src/wp-admin/includes/class-wp-list-table.php b/src/wp-admin/includes/class-wp-list-table.php
index f277a0b8a6..7cf6f0725f 100644
--- a/src/wp-admin/includes/class-wp-list-table.php
+++ b/src/wp-admin/includes/class-wp-list-table.php
@@ -1170,9 +1170,9 @@ class WP_List_Table {
 					$class[] = 'sorted';
 					$class[] = $current_order;
 				} else {
-					if ( in_array( strtolower( $desc_first ), array( 'desc', 'asc' ), true ) ) {
-						$order = 'asc' === strtolower( $desc_first ) ? 'desc' : 'asc';
-					} else {
+					$order = strtolower( $desc_first );
+
+					if ( ! in_array( $order, array( 'desc', 'asc' ), true ) ) {
 						$order = $desc_first ? 'desc' : 'asc';
 					}
 
@@ -1180,7 +1180,11 @@ class WP_List_Table {
 					$class[] = 'desc' === $order ? 'asc' : 'desc';
 				}
 
-				$column_display_name = '<a href="' . esc_url( add_query_arg( compact( 'orderby', 'order' ), $current_url ) ) . '"><span>' . $column_display_name . '</span><span class="sorting-indicator"></span></a>';
+				$column_display_name = sprintf(
+					'<a href="%s"><span>%s</span><span class="sorting-indicator"></span></a>',
+					esc_url( add_query_arg( compact( 'orderby', 'order' ), $current_url ) ),
+					$column_display_name
+				);
 			}
 
 			$tag   = ( 'cb' === $column_key ) ? 'td' : 'th';
diff --git a/tests/phpunit/tests/admin/includesListTable.php b/tests/phpunit/tests/admin/includesListTable.php
index 56b3be2d20..745b224e9c 100644
--- a/tests/phpunit/tests/admin/includesListTable.php
+++ b/tests/phpunit/tests/admin/includesListTable.php
@@ -303,7 +303,7 @@ class Tests_Admin_includesListTable extends WP_UnitTestCase {
 		$override_sortable_columns = array(
 			'author'   => array( 'comment_author', true ),
 			'response' => 'comment_post_ID',
-			'date'     => array( 'comment_date', 'dEsC' ), // The ordering support should be case insensitive.
+			'date'     => array( 'comment_date', 'dEsC' ), // The ordering support should be case-insensitive.
 		);
 
 		// Stub the get_sortable_columns() method.
@@ -324,8 +324,8 @@ class Tests_Admin_includesListTable extends WP_UnitTestCase {
 		$this->assertContains( '?orderby=comment_post_ID&#038;order=asc', $output, 'Mismatch of the default link ordering for comment response column. Should be asc.' );
 		$this->assertContains( 'column-response sortable desc', $output, 'Mismatch of CSS classes for the comment post ID column.' );
 
-		$this->assertContains( '?orderby=comment_date&#038;order=asc', $output, 'Mismatch of the default link ordering for comment author column. Should be asc.' );
-		$this->assertContains( 'column-date sortable desc', $output, 'Mismatch of CSS classes for the comment date column.' );
+		$this->assertContains( '?orderby=comment_date&#038;order=desc', $output, 'Mismatch of the default link ordering for comment date column. Should be asc.' );
+		$this->assertContains( 'column-date sortable asc', $output, 'Mismatch of CSS classes for the comment date column.' );
 	}
 
 	/**