diff --git a/typo3-probe.php b/typo3-probe.php
index 8c96e53..0881fc4 100644
--- a/typo3-probe.php
+++ b/typo3-probe.php
@@ -233,8 +233,7 @@ public function getStatus() {
 	 */
 	protected function checkCurrentDirectoryIsInIncludePath() {
 		$includePath = ini_get('include_path');
-		$delimiter = $this->isWindowsOs() ? ';' : ':';
-		$pathArray = $this->trimExplode($delimiter, $includePath);
+		$pathArray = $this->trimExplode(PATH_SEPARATOR, $includePath);
 		if (!in_array('.', $pathArray)) {
 			$status = new WarningStatus();
 			$status->setTitle('Current directory (./) is not in include path');
@@ -1160,7 +1159,7 @@ protected function isValidIp($ip) {
 	 */
 	protected function isWindowsOs() {
 		$windowsOs = FALSE;
-		if (stristr(PHP_OS, 'darwin') && stristr(PHP_OS, 'win')) {
+		if (!stristr(PHP_OS, 'darwin') && stristr(PHP_OS, 'win')) {
 			$windowsOs = TRUE;
 		}
 		return $windowsOs;
@@ -1326,4 +1325,4 @@ function printStatus($statuses) {
 			<p><strong><a href="https://github.com/7elix/TYPO3-Probe/issues" target="_blank">Report bugs for TYPO3 Probe</a></strong></p>
 		</footer>
 	</body>
-</html>
\ No newline at end of file
+</html>