diff --git a/sci-mathematics/twelf/metadata.xml b/sci-mathematics/twelf/metadata.xml
index d4994fb246a44..938124fd245e8 100644
--- a/sci-mathematics/twelf/metadata.xml
+++ b/sci-mathematics/twelf/metadata.xml
@@ -7,4 +7,7 @@
   logic programming and for the formalization of programming language
   theory.
   </longdescription>
+  <upstream>
+    <remote-id type="github">standardml/twelf</remote-id>
+  </upstream>
 </pkgmetadata>