diff --git a/wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php b/wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php
index 6c9611c87b..207198e54c 100644
--- a/wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php
+++ b/wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php
@@ -641,7 +641,9 @@ class WP_REST_Users_Controller extends WP_REST_Controller {
 			return new WP_Error( 'rest_user_invalid_id', __( 'Invalid user ID.' ), array( 'status' => 404 ) );
 		}
 
-		if ( email_exists( $request['email'] ) && $request['email'] !== $user->user_email ) {
+		$owner_id = email_exists( $request['email'] );
+
+		if ( $owner_id && $owner_id !== $id ) {
 			return new WP_Error( 'rest_user_invalid_email', __( 'Invalid email address.' ), array( 'status' => 400 ) );
 		}
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 7c859ab584..3a87ea9cf5 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.1-beta1-44640';
+$wp_version = '5.1-beta1-44641';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.