Novel tools and techniques for implementing a clamp assembly for disposable endoscopic sheaths are provided. A system includes a sheath, clamp assembly, and protective cover. The sheath may be configured to receive an instrument. The clamp assembly may include a first member coupled to a second member, wherein the first and second members may be placed in a clamping configuration and an open configuration. In the clamping configuration, the first member and the second member are configured to collapse a lumen of the sheath at a location between the first and second members, and in the open configuration the lumen is not collapsed between the first and second members. The protective cover may include a receiver configured to mate with the clamp assembly and to cause the clamp assembly to maintain the open configuration when the clamp assembly is mated with the receiver.