diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a48452aad..eb2aba269 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,5 +1,7 @@
 # Submitting issues
 
+**Must read:** [How to Report Bugs Effectively](http://www.chiark.greenend.org.uk/~sgtatham/bugs.html).
+
 ### Before you submit
 
 1. Submit **bugs/issues only**.