A composition comprising: A) a polypropylene, a propylene copolymer or a crystalline poly alpha-olefin copolymer possessing a first order transition or crystalline melting point as determined by differential scanning calorimetry, selected from polybutylene and poly(4-methylpentene), B) a LDPE having a density of 0.91 g/cm 3 to 0.94 g/cm 3, and C) at least one polymer compatibilizer being a crystalline block composite comprising: i) a crystalline ethylene based polymer; ii) a crystalline alpha-olefin based polymer; and iii) a block copolymer comprising a crystalline ethylene block and a crystalline alpha-olefin block, wherein the crystalline ethylene block is essentially the same composition as the crystalline ethylene based polymer in the block composite, and the crystalline alpha-olefin block is essentially the same composition as the crystalline alpha-olefin based polymer of the block composite, wherein component C) possesses a first order transition or crystalline melting point as determined by differential scanning calorimetry as described in the description, wherein component C) is present in an amount of from 0.5 wt % to 15 wt% based on the total weight of the composition, and wherein component C) has a Crystalline Block Composite Index of greater than 0.0 up to 1.0, wherein the Crystalline Block Composite Index is determined by using high temperature liquid chromatography on a first dimension HPLC column and a second dimension SEC column using either 1-decanol or decane with 200 ppm 2,6-di- tert -butyl-4-methylphenol as described in the description. A) a polypropylene, a propylene copolymer or a crystalline poly alpha-olefin copolymer possessing a first order transition or crystalline melting point as determined by differential scanning calorimetry, selected from polybutylene and poly(4-methylpentene), B) a LDPE having a density of 0.91 g/cm 3 to 0.94 g/cm 3, and C) at least one polymer compatibilizer being a crystalline block composite comprising: i) a crystalline ethylene based polymer; ii) a crystalline alpha-olefin based polymer; and iii) a block copolymer comprising a crystalline ethylene block and a crystalline alpha-olefin block, wherein the crystalline ethylene block is essentially the same composition as the crystalline ethylene based polymer in the block composite, and the crystalline alpha-olefin block is essentially the same composition as the crystalline alpha-olefin based polymer of the block composite, wherein component C) possesses a first order transition or crystalline melting point as determined by differential scanning calorimetry as described in the description, wherein component C) is present in an amount of from 0.5 wt % to 15 wt% based on the total weight of the composition, and wherein component C) has a Crystalline Block Composite Index of greater than 0.0 up to 1.0, wherein the Crystalline Block Composite Index is determined by using high temperature liquid chromatography on a first dimension HPLC column and a second dimension SEC column using either 1-decanol or decane with 200 ppm 2,6-di- tert -butyl-4-methylphenol as described in the description. i) a crystalline ethylene based polymer; ii) a crystalline alpha-olefin based polymer; and iii) a block copolymer comprising a crystalline ethylene block and a crystalline alpha-olefin block, wherein the crystalline ethylene block is essentially the same composition as the crystalline ethylene based polymer in the block composite, and the crystalline alpha-olefin block is essentially the same composition as the crystalline alpha-olefin based polymer of the block composite,