diff --git a/src/Adyen/Util/IpAddress.php b/src/Adyen/Util/IpAddress.php
index 18a9ba372..a077792fc 100644
--- a/src/Adyen/Util/IpAddress.php
+++ b/src/Adyen/Util/IpAddress.php
@@ -41,7 +41,12 @@ public function getAdyenIpAddresses()
     {
         $ipAddresses = array();
         foreach (self::$HOSTNAMES as $hostname) {
-            $ipAddresses = array_merge($ipAddresses, gethostbynamel($hostname));
+            $ipAddressesOfHostName = gethostbynamel($hostname);
+            
+            // gethostbynamel can return false if hostname could not be resolved
+            if (false !== $ipAddressesOfHostName) {
+                $ipAddresses = array_merge($ipAddresses, $ipAddressesOfHostName);
+            }
         }
         return $ipAddresses;
     }