diff --git a/handshake_server.go b/handshake_server.go
index 3a2ca85..ad30acf 100644
--- a/handshake_server.go
+++ b/handshake_server.go
@@ -353,7 +353,7 @@ func negotiateALPN(serverProtos, clientProtos []string, quic bool) (string, erro
 	if http11fallback {
 		return "", nil
 	}
-	return "", fmt.Errorf("tls: client requested unsupported application protocols (%s)", clientProtos)
+	return "", fmt.Errorf("tls: client requested unsupported application protocols (%q)", clientProtos)
 }
 
 // supportsECDHE returns whether ECDHE key exchanges can be used with this