From d166e94adf6d9a0efbd6354a0498c1051c44069b Mon Sep 17 00:00:00 2001
From: acelot <provaleriy@gmail.com>
Date: Wed, 12 Sep 2018 20:30:33 +0700
Subject: [PATCH] Fixed up extra keys validation

---
 src/Struct.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Struct.php b/src/Struct.php
index b3c846e..3ab9463 100644
--- a/src/Struct.php
+++ b/src/Struct.php
@@ -190,7 +190,7 @@ protected function validate(array $newData): void
         $extraKeys = array_keys(array_diff_key($newData, $props));
         if (!empty($extraKeys)) {
             throw new ValidationException(array_map(function ($extraKey) {
-                return [$extraKey => "Property \"${$extraKey}\" not defined in schema"];
+                return [$extraKey => "Property \"$extraKey\" not defined in schema"];
             }, $extraKeys));
         }