Why does Java Map take an untyped parameter for the get and remove methods?

I ran into a bug in my code where I was using the wrong key to fetch something from a Java map that I believed was strongly typed using Java generics. When looking at the Map Javadocs, many of the methods, including get and remove, take an Object as the parameter instead of type K (for a Map defined as Map). Why is this? Is there a good reason or is it an API design flaw?