diff --git a/lib/PayPal/Auth/OAuthTokenCredential.php b/lib/PayPal/Auth/OAuthTokenCredential.php
index 521de2a..949fb86 100644
--- a/lib/PayPal/Auth/OAuthTokenCredential.php
+++ b/lib/PayPal/Auth/OAuthTokenCredential.php
@@ -31,7 +31,7 @@ class OAuthTokenCredential extends PayPalResourceModel
      *
      * @var int $expiryBufferTime
      */
-    private static $expiryBufferTime = 120;
+    public static $expiryBufferTime = 120;
 
     /**
      * Client ID as obtained from the developer portal