diff --git a/wp-includes/rest-api/class-wp-rest-server.php b/wp-includes/rest-api/class-wp-rest-server.php
index cb19242bf1..2c49c8fc69 100644
--- a/wp-includes/rest-api/class-wp-rest-server.php
+++ b/wp-includes/rest-api/class-wp-rest-server.php
@@ -853,8 +853,6 @@ class WP_REST_Server {
 					$request->set_url_params( $args );
 					$request->set_attributes( $handler );
 
-					$request->sanitize_params();
-
 					$defaults = array();
 
 					foreach ( $handler['args'] as $arg => $options ) {
@@ -869,6 +867,8 @@ class WP_REST_Server {
 					if ( is_wp_error( $check_required ) ) {
 						$response = $check_required;
 					}
+
+					$request->sanitize_params();
 				}
 
 				if ( ! is_wp_error( $response ) ) {
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 9fdc7479e6..4aa9bca937 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-beta1-37942';
+$wp_version = '4.6-beta1-37943';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.