A composition comprising the following components: A) an ethylene/α-olefin/non-conjugated diene interpolymer; B) a peroxide; C) at least one multi-vinyl cyclic siloxane selected from Structure 1 below: Structure 1, wherein n is an integer greater than, or equal to, 1; and each R1 is independently selected from the following: a (C2-C4) alkenyl, or a H2C═C(R1a)—C(═O)—O—(CH2)m—, and wherein R1a is H or methyl, and m is an integer from 1 to 4; and each R2 is independently selected from the following: H, a (C1-C4) alkyl, a (C2-C4) alkenyl, a phenyl, or a H2C═C(R1b)—C(═O)—O—(CH2)m—, wherein R1b is H or methyl, and m is an integer from 1 to 4.