An electronic device having an enclosure is disclosed. The electronic device includes a hole disposed at least partially through the enclosure. The electronic device also includes a detector configured to provide at least one visual indication after being immersed in water. The detector may include a moisture-indicating portion and a light-permitting moisture-proof membrane. The detector may be disposed inside at least one of the enclosure and the hole such that at least a portion of the detector is visible through the hole from outside of the enclosure without dismantling or opening the electronic device. The distance between the light-permitting moisture-proof membrane and an opening of the hole in the enclosure may be less than the distance between the moisture-indicating portion and the opening of the hole.