diff --git a/lib/PayPal/Core/PayPalConfigManager.php b/lib/PayPal/Core/PayPalConfigManager.php
index c341bb12..d3700b37 100644
--- a/lib/PayPal/Core/PayPalConfigManager.php
+++ b/lib/PayPal/Core/PayPalConfigManager.php
@@ -99,9 +99,9 @@ public function get($searchKey)
             return $this->configs[$searchKey];
         } else {
             $arr = array();
-            if ($searchKey !== '') {
+            if (!empty($searchKey)) {
                 foreach ($this->configs as $k => $v) {
-                    if (strstr($k, $searchKey)) {
+                    if (strstr($k, (string)$searchKey)) {
                         $arr[$k] = $v;
                     }
                 }