diff --git a/Protocol.md b/Protocol.md
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@@ -1,5 +1,5 @@
 # General
-* Friendica uses [DFRN](https://macgirvin.com/spec/dfrn2.pdf) as message protocol. 
+* Friendica uses [DFRN](https://github.com/friendica/friendica/blob/master/spec/dfrn2.pdf) as message protocol. 
 * The messages uses [ActivityStreams](http://activitystrea.ms/head/activity-schema.html).
 * [Webfinger](https://code.google.com/p/webfinger/wiki/WebFingerProtocol) is used for the discovery of users
 * [Salmon](https://en.wikipedia.org/wiki/Salmon_%28protocol%29) is used as a message exchange protocol for replies and mentions.