You cannot claim his earnings. He is required to file his own return since he made more than $400 in self employment earnings.
This is from IRS Pub 501
Table 3.Other Situations When You Must File a 2016 Return
3.
You had net earnings from self-employment of at least $400. (See Schedule SE (Form 1040) and its instructions.)
https://www.irs.gov/publications/p501/ar02.html#en_US_2016_publink1000220714
