diff --git a/composer.json b/composer.json
index c10a561..952b3ba 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
     ],
     "require": {
         "php": ">=5.3.0",
-        "paypal/rest-api-sdk-php" : "*"
+        "paypal/rest-api-sdk-php" : "0.15.*"
     },
     "extra": {
         "installer-name": "PayPal"