diff --git a/README.md b/README.md
index 4162303..f8da646 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
 # plentymarkets-rest-client
+
 [![Latest Version on Packagist](https://img.shields.io/packagist/v/repat/plentymarkets-rest-client.svg?style=flat-square)](https://packagist.org/packages/repat/plentymarkets-rest-client)
 [![Total Downloads](https://img.shields.io/packagist/dt/repat/plentymarkets-rest-client.svg?style=flat-square)](https://packagist.org/packages/repat/plentymarkets-rest-client)
 
@@ -8,7 +9,8 @@ I'm not in anyway affiliated with Plentymarkets, nor do I get paid for this by a
 
 You can find the Plentymarkets documentation [here](https://developers.plentymarkets.com/):
 
-### Overview
+## Overview
+
 * Functions for the 4 HTTP verbs: GET, POST, PUT, DELETE
 * Automatic login and refresh if login is not valid anymore
 * Simple one-time configuration with PHP array (will be saved serialized in a file)
@@ -16,11 +18,13 @@ You can find the Plentymarkets documentation [here](https://developers.plentymar
 * Handle rate limiting (thanks [hepisec](http://github.com/hepisec))
 
 ## Installation
+
 Available via composer on [Packagist](https://packagist.org/packages/repat/plentymarkets-rest-client):
 
 `composer require repat/plentymarkets-rest-client`
 
 ## Usage
+
 ```php
 use repat\PlentymarketsRestClient\PlentymarketsRestClient;
 
@@ -45,6 +49,7 @@ $client = new PlentymarketsRestClient($configFilePath);
 ```
 
 It's possible to use the 4 HTTP verbs like this
+
 ```php
 $client->get($path, $parameterArray);
 $client->post($path, $parameterArray);
@@ -71,21 +76,27 @@ $client->singleCall("GET", $guzzleParameterArray);
 ```
 
 ### Errors
+
 * If there was an error with the call (=> guzzle throws an exception) all functions will return false
 * If the specified config file doesn't exist or doesn't include username/password/url, an exception will be thrown
 
 ## TODO
+
 * Refresh without new login but refresh-token
 
 ## Dependencies
+
 * [https://packagist.org/packages/nesbot/carbon](nesbot/carbon) for date comparison
 * [https://packagist.org/packages/guzzlehttp/guzzle](guzzlehttp/guzzle) for HTTP calls.
 * [https://packagist.org/packages/danielstjules/stringy](danielstjules/stringy) for string comparisons
 
 ## License
+
 * see [LICENSE](https://github.com/repat/plentymarkets-rest-client/blob/master/LICENSE) file
 
 ## Changelog
+
+* 0.1.11 PHP 8 Support & wait in case of _short period read limit reached_ error (thx [fwehrhausen](https://github.com/repat/plentymarkets-rest-client/pull/15))
 * 0.1.10 Allow dealing with Exceptions yourself by passing `true` as 3rd parameter
 * 0.1.9 Bugfix `isAccessTokenValid()` (thx [hochdruckspezialist](https://github.com/repat/plentymarkets-rest-client/pull/14))
 * 0.1.8 Update, so Carbon 2.0 can be used (thx [stefnats](https://github.com/repat/plentymarkets-rest-client/pull/12))
@@ -99,7 +110,8 @@ $client->singleCall("GET", $guzzleParameterArray);
 * 0.1 initial release
 
 ## Contact
-* Homepage: https://repat.de
+
+* Homepage: [https://repat.de](https://repat.de)
 * e-mail: repat@repat.de
 * Twitter: [@repat123](https://twitter.com/repat123 "repat123 on twitter")
 
diff --git a/composer.json b/composer.json
index 90b6e93..4f2f205 100644
--- a/composer.json
+++ b/composer.json
@@ -5,7 +5,7 @@
     "keywords": ["plentymarkets", "pm", "rest", "api", "client", "sdk"],
     "homepage": "https://github.com/repat/plentymarkets-rest-client",
     "license": "MIT",
-    "version" : "0.1.10",
+    "version" : "0.1.11",
     "authors": [
         {
             "name": "repat",
@@ -18,15 +18,18 @@
         },
         {
             "name": "daniel-mannheimer",
-            "email": "dm@actionmix.net",
+            "role": "Contributor"
+        },
+        {
+            "name": "fwehrhausen",
             "role": "Contributor"
         }
     ],
     "require": {
-        "php": "^7.0|^8.0",
-        "guzzlehttp/guzzle": "^7.0.1",
+        "php": "^5.6 | ^7.0 | ^8.0",
+        "guzzlehttp/guzzle": "^6.0 | ^7.0",
         "nesbot/carbon": "^1.22.1 | ^2.0",
-        "danielstjules/stringy": "2.3.2"
+        "danielstjules/stringy": "^2.4 | ^3.0"
     },
     "autoload": {
         "psr-4": { "repat\\PlentymarketsRestClient\\": "src/PlentymarketsRestClient" }
diff --git a/src/PlentymarketsRestClient/PlentymarketsRestClient.php b/src/PlentymarketsRestClient/PlentymarketsRestClient.php
index b1c2192..5e7dd24 100644
--- a/src/PlentymarketsRestClient/PlentymarketsRestClient.php
+++ b/src/PlentymarketsRestClient/PlentymarketsRestClient.php
@@ -16,6 +16,9 @@ class PlentymarketsRestClient
     const METHOD_PATCH = 'PATCH';
     const METHOD_DELETE = 'DELETE';
 
+    const WAIT_ERROR_SHORT_PERIOD_READ_LIMIT = 5;
+    const ERROR_SHORT_PERIOD_READ_LIMIT = 'short period read limit reached';
+
     const THROTTLING_PREFIX_LONG_PERIOD = 'X-Plenty-Global-Long-Period';
     const THROTTLING_PREFIX_SHORT_PERIOD = 'X-Plenty-Global-Short-Period';
     const THROTTLING_PREFIX_ROUTE = 'X-Plenty-Route';
@@ -87,16 +90,18 @@ public function singleCall($method, $path, $params = [])
             $response = $this->client->request($method, $this->config['url'] . $path, $params);
         } catch (\Exception $e) {
 
-            //for a better plentymarkets exception handling, sometimes the limit is not correctly
-            if (strpos('short period read limit reached', $e->getMessage())) {
-                sleep(5);
+            // For a better Plentymarkets exception handling. Sometimes the limit is not correct
+            if (s($e->getMessage())->contains(self::ERROR_SHORT_PERIOD_READ_LIMIT)) {
+                sleep(self::WAIT_ERROR_SHORT_PERIOD_READ_LIMIT);
                 $this->singleCall($method, $path, $params);
+                // TODO possible handle recursion errors
             }
 
             if ($this->handleExceptions === true) {
                 throw $e;
             }
-            return false;
+
+            return null;
         }
 
         $this->throttledOnLastRequest = false;