I'm building a pretty basic app, and one thing I want to do is pass an object as a parameter up through the service - async - impl instead of passing up a million separate parameters. so in async, I do something like this: import shared.Profile; ... public interface ProfileServiceAsync { public void addProfile(Profile inProf, AsyncCallback<Void> async); Now, profile is a class in com. ... .shared and I have the following in my ... .gwt.xml <source path='shared'/> That being said when I try to compile I get this error. [ERROR] Errors in 'file:/D:/projects/eclipse/workspace/.../src/com/.../client/ProfileServiceAsync.java' [ERROR] Line 11: No source code is available for type shared.Profile; did you forget to inherit a required module? Any ideas on this?