The following situation:

@RequestScoped class Foo {}
@Dependent class Bar extends Foo {}

results in this:

Exception in thread "main" org.jboss.weld.DefinitionException: WELD-000046 At most one scope may be specified on class Class [@Alternative, @Dependent, @RequestScoped]...
at org.jboss.weld.bean.AbstractClassBean.initScopeType(AbstractClassBean.java:297)
at org.jboss.weld.bean.AbstractBean.initialize(AbstractBean.java:147)
at org.jboss.weld.bean.AbstractClassBean.initialize(AbstractClassBean.java:146)
at org.jboss.weld.bean.ManagedBean.initialize(ManagedBean.java:199)
at org.jboss.weld.bootstrap.AbstractBeanDeployer.deploy(AbstractBeanDeployer.java:111)
at org.jboss.weld.bootstrap.BeanDeployment.deployBeans(BeanDeployment.java:151)
at org.jboss.weld.bootstrap.WeldBootstrap.deployBeans(WeldBootstrap.java:367)
at org.jboss.weld.environment.se.StartMain.go(StartMain.java:73)
at org.jboss.weld.environment.se.StartMain.main(StartMain.java:89)