diff --git a/README.md b/README.md
index 32a016e..5794520 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Reproduction repo for a `pip-tools` bug
 
-Issue: TODO
+Issue: https://github.com/jazzband/pip-tools/issues/1589
 
 ## Companion repositories: