diff --git a/wp-admin/admin-header.php b/wp-admin/admin-header.php
index 57da556a47..6ba4fe511f 100644
--- a/wp-admin/admin-header.php
+++ b/wp-admin/admin-header.php
@@ -96,7 +96,7 @@ if ( is_admin_bar_showing() )
 if ( is_rtl() )
 	$admin_body_class .= ' rtl';
 
-$admin_body_class .= ' branch-' . str_replace( '.', '-', floatval( $wp_version ) );
+$admin_body_class .= ' branch-' . str_replace( array( '.', ',' ), '-', floatval( $wp_version ) );
 $admin_body_class .= ' version-' . str_replace( '.', '-', preg_replace( '/^([.0-9]+).*/', '$1', $wp_version ) );
 $admin_body_class .= ' admin-color-' . sanitize_html_class( get_user_option( 'admin_color' ), 'fresh' );