Received a different US visa category than I applied for

I am from germany and an employee of a large US-based IT company. I recently applied for a B1/B2 and I went through the whole process. I then went to the consulate last week and they accepted my application and told me that they would ship my passport to me as I ordered. I just received my passport via the mail but when I checked everything, I noticed that instead of B1/B2 the visa only states B1. Is this just a human error or is there more to it? And most importantly, is there anything I can/should do about this to change it to a B1/B2 and how long would this take?