Passport validity and visa

Have a valid US passport until 4/2017 and Chinese visa valid until 4/2017. We are traveling to Japan which I understand is a country that does NOT need 6 month validity for entering (passport just needs to be valid for time spent in Japan). So going seems to be no problem and I just want to double check that re-entering should not be a problem into China (China is a country that requires 6 months validity for entering) even though her passport expires within a few months. We currently live in China so of course have a valid visa but want to double check.