diff --git a/Dev.md b/Dev.md
index 40ec755..510efde 100644
--- a/Dev.md
+++ b/Dev.md
@@ -50,7 +50,9 @@ Views into the process of Tahoe-LAFS hackery.
  * [coding standards](CodingStandards)
  * [How to write tests](HowToWriteTests)
  * Debugging:
-  * Debugging tips in tahoe-dev mailing list: <https://tahoe-lafs.org/pipermail/tahoe-dev/2013-April/008165.html>
+  * Debugging tips in tahoe-dev mailing list:
+    * <https://tahoe-lafs.org/pipermail/tahoe-dev/2013-April/008165.html>
+    * <https://tahoe-lafs.org/pipermail/tahoe-dev/2013-July/008579.html>
   * The [logging system](https://tahoe-lafs.org/trac/tahoe-lafs/browser/trunk/docs/logging.rst)
 
 ### Cool New Ideas We're Working On