diff --git a/wp-includes/class-wp-widget.php b/wp-includes/class-wp-widget.php
index 114328d499..0681d3715c 100644
--- a/wp-includes/class-wp-widget.php
+++ b/wp-includes/class-wp-widget.php
@@ -177,11 +177,17 @@ class WP_Widget {
 	 *
 	 * This function should be used in form() methods to create name attributes for fields to be saved by update()
 	 *
+	 * @since 4.4.0 Array format field names are now accepted.
+	 *
 	 * @param string $field_name Field name
 	 * @return string Name attribute for $field_name
 	 */
 	public function get_field_name($field_name) {
-		return 'widget-' . $this->id_base . '[' . $this->number . '][' . $field_name . ']';
+		if ( false === $pos = strpos( $field_name, '[' ) ) {
+			return 'widget-' . $this->id_base . '[' . $this->number . '][' . $field_name . ']';
+		} else {
+			return 'widget-' . $this->id_base . '[' . $this->number . '][' . substr_replace( $field_name, '][', $pos, strlen( '[' ) );
+		}
 	}
 
 	/**
@@ -190,6 +196,8 @@ class WP_Widget {
 	 * This function should be used in form() methods to create id attributes
 	 * for fields to be saved by {@see WP_Widget::update()}.
 	 *
+	 * @since 4.4.0 Array format field IDs are now accepted.
+	 *
 	 * @since 2.8.0
 	 * @access public
 	 *
@@ -197,7 +205,7 @@ class WP_Widget {
 	 * @return string ID attribute for `$field_name`.
 	 */
 	public function get_field_id( $field_name ) {
-		return 'widget-' . $this->id_base . '-' . $this->number . '-' . $field_name;
+		return 'widget-' . $this->id_base . '-' . $this->number . '-' . trim( str_replace( array( '[]', '[', ']' ), array( '', '-', '' ), $field_name ), '-' );
 	}
 
 	/**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e4208aeaba..df49039b63 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34779';
+$wp_version = '4.4-alpha-34780';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.