Lockers appear in Dr. Mario: Miracle Cure, where they are miracle cures that appear exclusively in vs. battles. Their main function is to temporarily prevent the opponent from rotating their capsules. After filling the gauge, the miracle cure will take effect as soon as the opponent placed their current capsule, after which the opponent's next capsule(s) cannot be rotated. This effect lasts for about 10 seconds. The identity of this miracle cure is indicated by a circle with an exclamation mark inside, which could be either this, the Reverser or the Booster. The aforementioned miracle cures can take effect concurrently, as long as their timers are not up.