diff --git a/README.md b/README.md
index b68ea63..41e0fc5 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,8 @@ This is a graph of the post flow of the `overchan.test` newsgroup over 4 years,
 
 ![network topology of 4 years](topology.png "changolia")
 
+[source code for map generation](https://github.com/nilesr/nntpchan-mapper)
+
 ## Donations
 
 Like this project? Why not help by funding it? This address pays for the server that runs `2hu-ch.org`