Hanning said two of his managers recently told him on separate occasions about women who asked them if their Tinder dates matched their photos.
The conversations made Hanning realize the need for something discreet to make patrons more comfortable.
The sign was initially only in the women's room, but soon expanded to the men's room and included gender-neutral pronouns, such as their instead of his or her.
The Huffington Post UK reported that restaurant staff is overwhelmed by the positive feeback from the signs.
"A sign that was designed purely for the safety of our female customers has caught the eyes of thousands (all genders), and you have all touched our hearts with your support, so thank you for this," a staff member said.
The Brickyard Twitter page has shared an image of the new sign in both restrooms Wednesday.