OK, I was gonna poke some fun- decided not to. But I did get a laugh out of it. Actually, I can understand your concern, especially if you bought used, for instance. And it's not like Canon stamps "Mark I" on the first version or something similar.
Question to the OP: Why do you still have a DC ( Sigma equivalent to EF-S ) lens with only a full frame camera ?
EOS 5D III, EOS 7D,EOS Rebel T4i, Canon 70-200 f/2.8 IS II, Canon 24-105L, Canon 18-135 IS STM, 1.4x TC III, 2.0x TC III, Σ 50mm f/1.4, Σ 17-50 OS, Σ 70-200 OS, Σ 50-500 OS, Σ 1.4x TC, Σ 2.0x TC, 580EXII(3), Canon SX-40, Canon S100
Fond memories: Rebel T1i, Canon 18-55 IS, Canon 55-250 IS, 18-135 IS (Given to a good home)...