diff --git a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
index 4537b85c5..ce3b98d5d 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
@@ -823,7 +823,7 @@ public class XmppConnection implements Runnable {
         final InetAddress address = socket.getInetAddress();
         final SSLSocket sslSocket = (SSLSocket) tlsFactoryVerifier.factory.createSocket(socket, address.getHostAddress(), socket.getPort(), true);
         SSLSocketHelper.setSecurity(sslSocket);
-        SSLSocketHelper.setHostname(sslSocket, account.getServer());
+        SSLSocketHelper.setHostname(sslSocket, IDN.toASCII(account.getServer()));
         SSLSocketHelper.setApplicationProtocol(sslSocket, "xmpp-client");
         if (!tlsFactoryVerifier.verifier.verify(account.getServer(), this.verifiedHostname, sslSocket.getSession())) {
             Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");