diff --git a/README.md b/README.md
index f478cd8..2349b3b 100644
--- a/README.md
+++ b/README.md
@@ -2,11 +2,11 @@
 
 Implementation of the basic functionality of the Modbus TCP and UDP based protocol using PHP. 
 
-**NOTE: This is a fork to fix & update the library code (and code alone). Notably, the tests are probably all broken.**
+**NOTE: This is a fork to fix & update the library code (and code alone).**
 
 > **What's new**
 > 
-> This fork adds a namespace and fixes issues encountered when porting to PHP 7
+> This fork adds a namespace and fixes issues encountered when porting to PHP 7, fixes old MS Windows specific tests
 
 
 ## Implemented features
@@ -26,6 +26,7 @@ Implementation of the basic functionality of the Modbus TCP and UDP based protoc
 ## Requirements
 
  * The PHP extension php_sockets.dll should be enabled (server php.ini file)
+ * PHP 5.5+
 
  
 ## Example
@@ -53,6 +54,15 @@ Use the `setTimeout($seconds)` and `setSocketTimeout($read_timeout_sec, $write_t
 
 Most of the code is (to some extent) commented and documented with PhpDoc. You should get useful tooltips in your IDE.
 
+## Tests
+
+To run the test suite, you need install the dependencies via composer, then
+run PHPUnit. 
+
+NB: PHP 5.6+ is required for tests
+
+    composer install
+    vendor/bin/phpunit
 
 ## GoogleCode legacy docs & downloads
 
diff --git a/composer.json b/composer.json
index d52d076..f643d4a 100644
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,7 @@
   "description": "PhpModbus with namespaces and updated to PHP 7",
   "license": "LGPL",
   "require": {
-    "php": "^5.3.2 || ^7.0",
+    "php": "^5.5 || ^7.0",
     "ext-sockets": "*"
   },
   "require-dev": {
diff --git a/tests/ModbusMaster/MockServerTestCase.php b/tests/ModbusMaster/MockServerTestCase.php
index b22f309..43d902f 100644
--- a/tests/ModbusMaster/MockServerTestCase.php
+++ b/tests/ModbusMaster/MockServerTestCase.php
@@ -23,7 +23,7 @@ abstract class MockServerTestCase extends TestCase
                 $clientData[] = $output;
             });
 
-            if ('WIN' !== strtoupper(substr(PHP_OS, 0, 3))) {
+            if (strpos(PHP_OS, 'WIN') === false) {
                 // wait to spin up. needed for linux. unnessecary on Windows 10.
                 // Ugly but even with 150ms sleep test run faster on Linux
                 usleep(150000);