NPE in InterceptorBindingType.unwrap when using seam-security-3.1.0.Final

When deploying JBpm 5.3.0.Final Guvnor in JBoss AS 7.1.3, an exception is thrown during deployment:
Caused by: java.lang.NullPointerException
at org.jboss.weld.interceptor.InterceptorBindingType.unwrap(InterceptorBindingType.java:30)
at org.jboss.weld.bean.InterceptorImpl.getInterceptorBindings(InterceptorImpl.java:80)
at org.jboss.weld.bean.InterceptorImpl.toString(InterceptorImpl.java:120)
at java.text.MessageFormat.subformat(MessageFormat.java:1246) [rt.jar:1.6.0_05]
at java.text.MessageFormat.format(MessageFormat.java:836) [rt.jar:1.6.0_05]
at java.text.Format.format(Format.java:140) [rt.jar:1.6.0_05]
at java.text.MessageFormat.format(MessageFormat.java:812) [rt.jar:1.6.0_05]
at ch.qos.cal10n.MessageConveyor.getMessage(MessageConveyor.java:89)
at org.jboss.weld.logging.WeldMessageConveyor.getMessage(WeldMessageConveyor.java:66)
at org.slf4j.cal10n.LocLogger.trace(LocLogger.java:72)
at org.jboss.weld.bean.AbstractBean.initDefaultQualifiers(AbstractBean.java:215)
at org.jboss.weld.bean.AbstractBean.initQualifiers(AbstractBean.java:209)
at org.jboss.weld.bean.ManagedBean.<init>(ManagedBean.java:281)
at org.jboss.weld.bean.InterceptorImpl.<init>(InterceptorImpl.java:63)
at org.jboss.weld.bean.InterceptorImpl.of(InterceptorImpl.java:59)
at org.jboss.weld.bootstrap.AbstractBeanDeployer.createInterceptor(AbstractBeanDeployer.java:228)
at org.jboss.weld.bootstrap.BeanDeployer.createBeans(BeanDeployer.java:137)
at org.jboss.weld.bootstrap.BeanDeployment.createBeans(BeanDeployment.java:204)
at org.jboss.weld.bootstrap.WeldBootstrap.deployBeans(WeldBootstrap.java:350)
at org.jboss.as.weld.WeldContainer.start(WeldContainer.java:82)
at org.jboss.as.weld.services.WeldService.start(WeldService.java:76)

(Please see the forum reference for more details.)

I'm not sure if this is a bug in weld, or it's seam-security that doesn't implement an interceptor properly (it's org.jboss.seam.security.SecurityInterceptor that causes the problem). If I add a null check in the unwrap method (and rebuild the weld-core-1.1.9 module), guvnor starts and works properly.