diff --git a/doc/doap.xml b/doc/doap.xml
index 234a5fc22..fa3893f88 100644
--- a/doc/doap.xml
+++ b/doc/doap.xml
@@ -47,12 +47,14 @@
         <foaf:homepage>https://www.zash.se/</foaf:homepage>
       </foaf:Person>
     </maintainer>
+    <implements rdf:resource="https://www.rfc-editor.org/info/rfc4627"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc5802"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc6120"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc6121"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc6122"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc6331"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc6455"/>
+    <implements rdf:resource="https://www.rfc-editor.org/info/rfc6901"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc7233"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc7301"/>
     <implements rdf:resource="https://www.rfc-editor.org/info/rfc7395"/>