Currently we have a class that has protected constructors (used mostly for testing purposes), however, Pico tries to instantiate that object using those constructors, instead of the less greedy (but still public) other constructors. A work around it to register it with params to indicate to use the noarg constructor: internalContainer.registerComponentImplementation( UpgradeManager.class, UpgradeManagerImpl.class, Collections.EMPTY_LIST); The problem appears to be that ConstructorInjectionComponentAdapter.getGreediestSatisifableConstructor() can return a constructor which then barfs in InstantiatingComponentAdapter.newInstance(). I think that this could be solved by making allowNonPublicClasses protected in InstantiatingComponentAdapter ? On another note - is Satisifable the correct spelling?