diff --git a/docs/CONTRIBUTING.md b/docs/CONTRIBUTING.md
index 0c8b2c91..793fc7d5 100644
--- a/docs/CONTRIBUTING.md
+++ b/docs/CONTRIBUTING.md
@@ -62,6 +62,10 @@ Common things a reviewer will look for:
 
    Submissions must pass all [regression test cases](Debugging.md).
 
+   When fixing a defect in the code, submitters should have a general
+   understanding of the root cause of that defect, and the fix should
+   target that root cause.
+
    Code submissions should not contain excessive debugging code,
    debugging options, nor run-time debug logging.