diff --git a/gulliver/system/class.bootstrap.php b/gulliver/system/class.bootstrap.php
index 9c83ed10e..78a8a137a 100644
--- a/gulliver/system/class.bootstrap.php
+++ b/gulliver/system/class.bootstrap.php
@@ -2917,5 +2917,32 @@ class Bootstrap
 		        return $url;
 		    }
 		}
-	}
+    /**
+    * isWinOs
+    *
+    * @return true if the 3 first letters of PHP_OS got 'WIN', otherwise false.
+    */
+    function isWinOs()
+    {
+        return strtoupper(substr(PHP_OS, 0, 3)) == "WIN";
+    }
+    /**
+    * isNTOs
+    *
+    * @return true if PHP_OS is 'WINNT', otherwise false.
+    */
+    function isNTOs()
+    {
+        return PHP_OS == "WINNT";
+    }
+    /**
+    * isLinuxOs
+    *
+    * @return true if PHP_OS (upper text) got 'LINUX', otherwise false.
+    */
+    function isLinuxOs()
+    {
+        return strtoupper(PHP_OS) == "LINUX";
+    }
+}
 
diff --git a/workflow/engine/bin/tasks/cliWorkspaces.php b/workflow/engine/bin/tasks/cliWorkspaces.php
index 3d6b0bb8c..5bce04b33 100755
--- a/workflow/engine/bin/tasks/cliWorkspaces.php
+++ b/workflow/engine/bin/tasks/cliWorkspaces.php
@@ -384,7 +384,7 @@ function run_workspace_backup($args, $opts) {
   $filesize = array_key_exists("filesize", $opts) ? $opts['filesize'] : -1;
   if($filesize >= 0)
   {
-      if(!G::isLinuxOs()){
+      if(!Bootstrap::isLinuxOs()){
             CLI::error("This is not a Linux enviroment, cannot use this filesize [-s] feature.\n");
             return;
       }
@@ -429,7 +429,7 @@ function run_workspace_restore($args, $opts) {
     $multiple = array_key_exists("multiple", $opts);
     $dstWorkspace = $args[1];
     if(!empty($multiple)){
-        if(!G::isLinuxOs()){
+        if(!Bootstrap::isLinuxOs()){
             CLI::error("This is not a Linux enviroment, cannot use this multiple [-m] feature.\n");
             return;
         }