I can't place my Mocked class files in the src/main/test folder?

I have a mocked class which simply extends a class in src/main/java/a/. It is configured by my test configuration xml:

<bean id="myService" class="a.b.c.MyService">
</bean>

My build was fine when my mocked class lived in src/main/java/a/. When I moved it to src/main/test/a/, my build breaks and IntelliJ tells me that it can't find the file. Can I not stick mock classes in the test directory? I don't need those mock classes to end up in the war.