A safety knife may include a housing defining an internal cavity, a blade coupled to the housing, and a sheath slideably engaged with the housing. The sheath may translate into the internal cavity of the housing to expose the blade. A switch may be pivotally coupled to the housing and may release the sheath from a locked position in response to depression of the switch. A locking arm may be pivotally coupled to the sheath with a projection that locks the sheath in an extended position by engaging an internal wall of the housing. A pawl may be pivotally coupled to the switch to depress the locking arm. The sheath includes a ridge that engages the pawl and rotates the pawl from a fully extended position.