diff --git a/core-bundle/src/Resources/contao/library/Contao/Environment.php b/core-bundle/src/Resources/contao/library/Contao/Environment.php
index <HASH>..<HASH> 100644
--- a/core-bundle/src/Resources/contao/library/Contao/Environment.php
+++ b/core-bundle/src/Resources/contao/library/Contao/Environment.php
@@ -548,7 +548,7 @@ class Environment
 		}
 
 		// Android tablets are not mobile (see #4150)
-		if ($os == 'Android' && stripos('mobile', $ua) === false)
+		if ($os == 'android' && stripos($ua, 'mobile') === false)
 		{
 			$mobile = false;
 		}
[Core] Correctly detect Android tablets in the `Environment` class (see #<I>)