A helmet with a visor includes structures that engage to prevent inadvertent retraction of the visor. The visor may be pressed against a shoulder formed around the face opening of the helmet responsive to an inward force. Arms securing the visor the helmet may be include a slot permitting sliding to facilitate this movement. The arms may include an arcuate slot and a radial slot engaging a guide pin mounted to the helmet. With the visor down, the guide pin slides within the radial slot. A protrusion on the visor may be urged into a receptacle on the helmet in response to an inward force. A latch may engage the helmet when the visor is down and be releasable manually.