diff --git a/lib/private/Http/Client/DnsPinMiddleware.php b/lib/private/Http/Client/DnsPinMiddleware.php
index f5e6214a4ab..9a19bd5830e 100644
--- a/lib/private/Http/Client/DnsPinMiddleware.php
+++ b/lib/private/Http/Client/DnsPinMiddleware.php
@@ -125,7 +125,7 @@ class DnsPinMiddleware {
 					$ports[] = (string)$port;
 				}
 
-				$targetIps = $this->dnsResolve(idn_to_utf8($hostName), 0);
+				$targetIps = $this->dnsResolve(idn_to_utf8($hostName, IDNA_DEFAULT, INTL_IDNA_VARIANT_UTS46), 0);
 
 				$curlResolves = [];
 
diff --git a/lib/private/Http/Client/LocalAddressChecker.php b/lib/private/Http/Client/LocalAddressChecker.php
index 2b91dbfdb9d..c85b18eb8bd 100644
--- a/lib/private/Http/Client/LocalAddressChecker.php
+++ b/lib/private/Http/Client/LocalAddressChecker.php
@@ -78,7 +78,7 @@ class LocalAddressChecker {
 			throw new LocalServerException('Could not detect any host');
 		}
 
-		$host = idn_to_utf8(strtolower(urldecode($host)));
+		$host = idn_to_utf8(strtolower(urldecode($host)), IDNA_DEFAULT, INTL_IDNA_VARIANT_UTS46);
 		// Remove brackets from IPv6 addresses
 		if (strpos($host, '[') === 0 && substr($host, -1) === ']') {
 			$host = substr($host, 1, -1);