RedisTemplate + Lua script: command arguments must be strings or integers

Question

I want to atomically insert or update a key, insert this key into an index and, optionally, increment a count. To this end, I wrote the following Lua script. In this script, KEYS[1] is the element key, KEYS[2] is the index key, ARGV[1] is the object stored at KEYS[1] and ARGV[2] is a score.

if not redis.call('EXISTS', KEYS[1]) then
  redis.call('INCR', KEYS[2] .. ":num");
end
redis.call('SET', KEYS[1], ARGV[1]);
redis.call('ZADD', KEYS[2] .. ":idx", tonumber(ARGV[2]), KEYS[1]);

To access Redis, I use a RedisTemplate<String, Object> instance which uses GenericFastJsonRedisSerializer to serialize values. A small working example:

public class Main {
    public static void main(String[] args) {
        RedisStandaloneConfiguration configuration = new RedisStandaloneConfiguration();
        configuration.setHostName("localhost");
        configuration.setPort(6379);
        LettuceConnectionFactory connectionFactory = new LettuceConnectionFactory(configuration);
        connectionFactory.afterPropertiesSet();

        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setDefaultSerializer(new GenericFastJsonRedisSerializer());
        template.setDefaultSerializer(new GenericFastJsonRedisSerializer());
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(new GenericFastJsonRedisSerializer());
        template.setHashKeySerializer(new GenericFastJsonRedisSerializer());
        template.setHashValueSerializer(new GenericFastJsonRedisSerializer());
        template.setConnectionFactory(connectionFactory);
        template.afterPropertiesSet();

        RedisScript<Object> script = RedisScript.of(new PathResource(Paths.get("my-script.lua"))); // <- above script
        template.execute(script, Arrays.asList("value-key", "index-key"), new Object(), 1.0);
    }
}

However, when I run the Lua script, I get the following error:

@user_script: 14: Lua redis() command arguments must be strings or integers

I suppose, this is because the serializer also serializes the score, so Lua cannot read it as number anymore. Hence, how can I avoid that the serializer is applied to all arguments, and only translating my object to JSON?