For example:
user=> (import java.util.Map)
java.util.Map
user=> (definterface Foo (^void foo [^Map map]))
user.Foo
user=> (deftype Bar [] Foo (foo [this m]))
CompilerException java.lang.NoClassDefFoundError: java/lang/Map, compiling:(NO_SOURCE_PATH:3:1)
user=> (definterface Foo2 (^void foo2 [^java.util.Map map]))
user.Foo2
user=> (deftype Bar2 [] Foo2 (foo2 [this m]))
user.Bar2
The attempt to type-hint with just Map fails; you have to use java.util.Map to get a usable interface definition.