diff --git a/lib/PayPal/Core/PayPalConfigManager.php b/lib/PayPal/Core/PayPalConfigManager.php
index a7ee1ca..c341bb1 100644
--- a/lib/PayPal/Core/PayPalConfigManager.php
+++ b/lib/PayPal/Core/PayPalConfigManager.php
@@ -99,9 +99,11 @@ class PayPalConfigManager
             return $this->configs[$searchKey];
         } else {
             $arr = array();
-            foreach ($this->configs as $k => $v) {
-                if (strstr($k, $searchKey)) {
-                    $arr[$k] = $v;
+            if ($searchKey !== '') {
+                foreach ($this->configs as $k => $v) {
+                    if (strstr($k, $searchKey)) {
+                        $arr[$k] = $v;
+                    }
                 }
             }