There are well over a million unexploded landmines around the world. Many of these devices outlast the conflicts they were intended for, only to later maim or kill innocent civilians. In many cases the locations of landmines are forgotten or lost, making the task of de-mining extremely difficult, dangerous and time-consuming. What is needed is a solution to this problem that protects innocent civilians and reduces the need for costly de-mining. It is a given that militaries will not likely voluntarily abolish the use of landmines, therefore any solution must take that into account. I propose a simple solution to the problem that meets all of the above criteria: Landmines should be manufactured with a built-in time-limited safety switch. After a certain amount of time, the mine simply will not explode anymore. The safety switch could be designed in a number of ways -- one embodiment would have it rust or dissolve over time by exposure to air and/or water. Another embodiment might base the switch on the decay of an isotope with a short half-life. Organic substances that are designed to degrade over time, perhaps by exposure to natural bacteria, could also be used. The time limit could be set to several years, or perhaps a decade, at most. Deactivated mines could be reactivead by simply replacing the switches. There are probably many other alternatives to accomplish the automatic time-limited self-deactivation of landmines. Getting landmine manufacturers to adopt such a technology is probably more achievable than getting them to stop making landmines altogether. This innovation could save a lot of lives and limbs.