diff --git a/wp-includes/class-wp-user.php b/wp-includes/class-wp-user.php
index fb79242f5f..620aecd024 100644
--- a/wp-includes/class-wp-user.php
+++ b/wp-includes/class-wp-user.php
@@ -240,7 +240,7 @@ class WP_User {
 
 		if ( ! $user = $wpdb->get_row(
 			$wpdb->prepare(
-				"SELECT * FROM $wpdb->users WHERE $db_field = %s",
+				"SELECT * FROM $wpdb->users WHERE $db_field = %s LIMIT 1",
 				$value
 			)
 		) ) {
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e97f37c29e..d6ffc6ed30 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43650';
+$wp_version = '5.0-alpha-43651';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.