So my 3 year old freaked out when my 1 year old son got birthday gifts? lol?

OK so I have a 3 year old son and a 1 year old son. My younger son turned 1 on Wednesday. HE opened a couple gifts and my older son got SO mad! We have been telling him several days in advance that his brother's birthday is coming up and he will get gifts and things like that. He was perfectly fine with it until he actually got the gifts. lol Well, his actual birthday party is this tomorrow. Any suggestions on how I can make him feel better about the whole thing? We have gotten him a few little gifts of his own to open Saturday also. Would really like to avoid a meltdown at this party. lol All advice / experiences is appreciated. :-)