Alerta 'We have a duplicate' ao gerar JAR no maven 2

Boa noite,

Pessoal, estou tentando gerar um .jar com maven 2, só que na hora de gerar recebo uma mensagem de alerta:

...
[WARNING] We have a duplicate org/bouncycastle/x509/extension/X509ExtensionUtil.class in C:\Users\renato.rudolf\.m2\repository\org\bouncycastle\bcprov-jdk14\1.38\bcprov-jdk14-1.38.jar
[WARNING] We have a duplicate org/bouncycastle/x509/util/LDAPStoreHelper.class in C:\Users\renato.rudolf\.m2\repository\org\bouncycastle\bcprov-jdk14\1.38\bcprov-jdk14-1.38.jar
[WARNING] We have a duplicate org/bouncycastle/cms/CMSAttributeTableGenerationException.class in C:\Users\renato.rudolf\.m2\repository\org\bouncycastle\bcmail-jdk14\1.38\bcmail-jdk14-1.38.jar
[WARNING] We have a duplicate org/bouncycastle/cms/CMSAttributeTableGenerator.class in C:\Users\renato.rudolf\.m2\repository\org\bouncycastle\bcmail-jdk14\1.38\bcmail-jdk14-1.38.jar
...

Agora se removo todas as dependencias no pom.xml, funciona normal, alguem sabe como resolver ?