diff --git a/lib/private/security/trusteddomainhelper.php b/lib/private/security/trusteddomainhelper.php
index 7d7cd5196b..c1a397dd52 100644
--- a/lib/private/security/trusteddomainhelper.php
+++ b/lib/private/security/trusteddomainhelper.php
@@ -78,7 +78,7 @@ class TrustedDomainHelper {
 		if (preg_match(Request::REGEX_LOCALHOST, $domain) === 1) {
 			return true;
 		}
-		return in_array($domain, $trustedList);
+		return in_array($domain, $trustedList, true);
 	}
 
 }
diff --git a/tests/lib/security/trusteddomainhelper.php b/tests/lib/security/trusteddomainhelper.php
index c8d5ffa587..52a8f1be63 100644
--- a/tests/lib/security/trusteddomainhelper.php
+++ b/tests/lib/security/trusteddomainhelper.php
@@ -64,6 +64,8 @@ class TrustedDomainHelperTest extends \Test\TestCase {
 			// do not trust invalid localhosts
 			[$trustedHostTestList, 'localhost:1:2', false],
 			[$trustedHostTestList, 'localhost: evil.host', false],
+			// do not trust casting
+			[[1], '1', false],
 		];
 	}