"java.security.KeyStoreException: TrustedCertEntry not supported" when using a PKCS12 keystore

Issue

When trying to add a trusted certificat into my keystore, I get this error:

java.security.KeyStoreException: TrustedCertEntry not supported
    at sun.security.pkcs12.PKCS12KeyStore.engineSetCertificateEntry(PKCS12KeyStore.java:654)
    at java.security.KeyStore.setCertificateEntry(KeyStore.java:970)
    at sun.security.tools.KeyTool.addTrustedCert(KeyTool.java:2637)
    at sun.security.tools.KeyTool.doCommands(KeyTool.java:1009)
    at sun.security.tools.KeyTool.run(KeyTool.java:340)
    at sun.security.tools.KeyTool.main(KeyTool.java:333)