diff --git a/setup/setuputils.class.inc.php b/setup/setuputils.class.inc.php
index b3727f207..a5c7643b8 100644
--- a/setup/setuputils.class.inc.php
+++ b/setup/setuputils.class.inc.php
@@ -551,15 +551,17 @@ class SetupUtils
 		SetupPage::log('Info - PHP functions disabled: '.implode(', ', $aDisabled));
 		if (in_array('exec', $aDisabled))
 		{
-			$aResult[] = new CheckResult(CheckResult::ERROR, "The PHP exec() function has been disabled on this server");
+			return new CheckResult(CheckResult::ERROR, "The PHP exec() function has been disabled on this server");
 		}
 
-		$sEscapedGraphvizPath = \escapeshellarg($sGraphvizPath);
-		if (!is_file($sEscapedGraphvizPath) || ! is_executable($sEscapedGraphvizPath)){
+		clearstatcache();
+		if (!is_file($sGraphvizPath) || ! is_executable($sGraphvizPath)){
 			//N°3412 avoid shell injection
-			return new CheckResult(CheckResult::WARNING, "$sGraphvizPath could not be executed: Please make sure it is installed and in the path");
+			return new CheckResult(CheckResult::ERROR, "$sGraphvizPath could not be executed: Please make sure it is installed and in the path");
 		}
 
+		$sGraphvizPath = escapeshellcmd($sGraphvizPath);
+
 		// availability of dot / dot.exe
 		if (empty($sGraphvizPath))
 		{
@@ -574,10 +576,6 @@ class SetupUtils
 		{
 			$oResult = new CheckResult(CheckResult::INFO, "dot is present: ".$aOutput[0]);
 		}
-		elseif ($iRetCode == 1)
-		{
-			$oResult = new CheckResult(CheckResult::WARNING, "dot could not be found: ".implode(' ', $aOutput)." - Please make sure it is installed and in the path.");
-		}
 		else
 		{
 			$oResult = new CheckResult(CheckResult::WARNING, "dot could not be executed (retcode=$iRetCode): Please make sure it is installed and in the path");
diff --git a/test/setup/SetupUtilsTest.php b/test/setup/SetupUtilsTest.php
new file mode 100644
index 000000000..3ce4cee77
--- /dev/null
+++ b/test/setup/SetupUtilsTest.php
@@ -0,0 +1,67 @@
+<?php
+
+
+namespace Combodo\iTop\Test\UnitTest\Setup;
+
+use Combodo\iTop\Test\UnitTest\ItopTestCase;
+use SetupUtils;
+
+
+/**
+ * Class SetupUtilsTest
+ *
+ * @runTestsInSeparateProcesses
+ * @preserveGlobalState disabled
+ * @backupGlobals disabled
+ *
+ * @covers SetupUtils
+ *
+ * @since 2.7.4 N°3412
+ * @package Combodo\iTop\Test\UnitTest\Setup
+ */
+class SetupUtilsTest extends ItopTestCase
+{
+	protected function setUp()
+	{
+		parent::setUp();
+
+		require_once APPROOT.'setup/setuputils.class.inc.php';
+		require_once APPROOT.'setup/setuppage.class.inc.php';
+	}
+
+	/**
+	 * @dataProvider CheckGravitzProvider
+	 */
+	public function testCheckGravitz($sScriptPath, $iSeverity, $sLabel){
+		/** @var \CheckResult $oCheck */
+		$oCheck = SetupUtils::CheckGraphviz($sScriptPath);
+		$this->assertEquals($iSeverity, $oCheck->iSeverity);
+		$this->assertContains($sLabel, $oCheck->sLabel);
+	}
+
+	public function CheckGravitzProvider(){
+		if (substr(PHP_OS,0,3) === 'WIN'){
+			return [];
+		}
+
+		return [
+			"bash injection" => [
+				"touch /tmp/toto",
+				0,
+				"could not be executed: Please make sure it is installed and in the path",
+			],
+			"command ok" => [
+				"/usr/bin/whereis",
+				2,
+				"",
+			],
+			"command failed" => [
+				"/bin/ls",
+				1,
+				"dot could not be executed (retcode=2): Please make sure it is installed and in the path",
+			]
+		];
+	}
+
+
+}