diff --git a/PHPCI/Helper/CommandExecutor.php b/PHPCI/Helper/CommandExecutor.php
index a422d970..70bfcff5 100644
--- a/PHPCI/Helper/CommandExecutor.php
+++ b/PHPCI/Helper/CommandExecutor.php
@@ -127,7 +127,7 @@ class CommandExecutor
             }
 
             // Use "where" for windows and "which" for other OS
-            $findCmd       = (strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN') ? 'which' : 'where';
+            $findCmd       = IS_WIN ? 'which' : 'where';
             $findCmdResult = trim(shell_exec($findCmd . ' ' . $bin));
 
             if (!empty($findCmdResult)) {
diff --git a/PHPCI/Model/Build/RemoteGitBuild.php b/PHPCI/Model/Build/RemoteGitBuild.php
index 43d1e6f7..4faf2557 100644
--- a/PHPCI/Model/Build/RemoteGitBuild.php
+++ b/PHPCI/Model/Build/RemoteGitBuild.php
@@ -67,7 +67,11 @@ class RemoteGitBuild extends Build
         $success = $builder->executeCommand('git clone -b %s %s "%s"', $this->getBranch(), $this->getCloneUrl(), $cloneTo);
 
         if (!empty($commit) && $commit != 'Manual') {
-            $builder->executeCommand('cd "%s" && git checkout %s', $cloneTo, $this->getCommitId());
+            $cmd = 'cd "%s" && git checkout %s';
+            if (IS_WIN) {
+                $cmd = 'cd /d "%s" && git checkout %s';
+            }
+            $builder->executeCommand($cmd, $cloneTo, $this->getCommitId());
         }
 
         return $success;
@@ -97,7 +101,11 @@ class RemoteGitBuild extends Build
         $commit = $this->getCommitId();
 
         if (!empty($commit) && $commit != 'Manual') {
-            $builder->executeCommand('cd "%s" && git checkout %s', $cloneTo, $this->getCommitId());
+            $cmd = 'cd "%s" && git checkout %s';
+            if (IS_WIN) {
+                $cmd = 'cd /d "%s" && git checkout %s';
+            }
+            $builder->executeCommand($cmd, $cloneTo, $this->getCommitId());
         }
 
         // Remove the key file:
diff --git a/PHPCI/Plugin/Codeception.php b/PHPCI/Plugin/Codeception.php
index bd168145..802d3540 100644
--- a/PHPCI/Plugin/Codeception.php
+++ b/PHPCI/Plugin/Codeception.php
@@ -70,6 +70,9 @@ class Codeception implements \PHPCI\Plugin
             }
 
             $cmd = 'cd "%s" && ' . $codecept . ' run -c "%s"';
+            if (IS_WIN) {
+                $cmd = 'cd /d "%s" && ' . $codecept . ' run -c "%s"';
+            }
             $success = $this->phpci->executeCommand($cmd, $this->phpci->buildPath, $this->phpci->buildPath . $configPath);
 
             return $success;
diff --git a/PHPCI/Plugin/Composer.php b/PHPCI/Plugin/Composer.php
index 0b89afe0..d40ac100 100644
--- a/PHPCI/Plugin/Composer.php
+++ b/PHPCI/Plugin/Composer.php
@@ -46,7 +46,7 @@ class Composer implements \PHPCI\Plugin
             return false;
         }
         $cmd = '';
-        if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
+        if (IS_WIN) {
             $cmd = 'php ';
         }
         $cmd .= $composerLocation . ' --no-ansi --no-interaction ';
diff --git a/PHPCI/Plugin/Grunt.php b/PHPCI/Plugin/Grunt.php
index 477a4849..ddbe7aa3 100644
--- a/PHPCI/Plugin/Grunt.php
+++ b/PHPCI/Plugin/Grunt.php
@@ -60,12 +60,19 @@ class Grunt implements \PHPCI\Plugin
     public function execute()
     {
         // if npm does not work, we cannot use grunt, so we return false
-        if (!$this->phpci->executeCommand('cd %s && npm install', $this->directory)) {
+        $cmd = 'cd %s && npm install';
+        if (IS_WIN) {
+            $cmd = 'cd /d %s && npm install';
+        }
+        if (!$this->phpci->executeCommand($cmd, $this->directory)) {
             return false;
         }
 
         // build the grunt command
         $cmd = 'cd %s && ' . $this->grunt;
+        if (IS_WIN) {
+            $cmd = 'cd /d %s && ' . $this->grunt;
+        }
         $cmd .= ' --no-color';
         $cmd .= ' --gruntfile %s';
         $cmd .= ' %s'; // the task that will be executed
diff --git a/vars.php b/vars.php
index 5725805e..46b88c79 100644
--- a/vars.php
+++ b/vars.php
@@ -25,3 +25,8 @@ if (!defined('ENABLE_SHELL_PLUGIN')) {
 if (!defined('PHPCI_IS_CONSOLE')) {
     define('PHPCI_IS_CONSOLE', false);
 }
+
+$isWin = (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') ? true : false;
+if (!defined('IS_WIN')) {
+    define('IS_WIN', $isWin);
+}