The present disclosure provides a flexible container. In an embodiment, the flexible container includes a first multilayer film and a second multilayer film. Each multilayer film comprises a seal layer. The multilayer films are arranged such that the seal layers oppose each other and the second multilayer film is superimposed on the first multilayer film. The multilayer films are sealed along a common peripheral edge. The flexible container includes a fitment. The fitment comprises a base. The base comprises a polymeric blend of from 60 wt % to 90 wt % ethylene/α-olefin multi-block copolymer and from 40 wt % to 10 wt % high density polyethylene (HDPE). The flexible container includes a fitment seal comprising the base located between the multilayer films. The base is sealed to each multilayer film at a portion of the common peripheral edge.