Locking assemblies for surgical clamping and cutting instruments include a locking member and a switch. A drive member may be configured to releasably engage a knife and/or a shuttle of the surgical instrument for translating the knife and/or shuttle in a distal direction through a firing stroke. The locking member is movable from a first position permitting distal translation of the drive member through the firing stroke, and a second position inhibiting distal translation of the drive member through the firing stroke. A switch, when proximally positioned, releasably engages the locking member to maintain the locking member in the first position. The switch disengages from the locking member when the switch is moved to a distal position.