diff --git a/Patches.md b/Patches.md
index c23d4d2..2ac93bf 100644
--- a/Patches.md
+++ b/Patches.md
@@ -10,7 +10,7 @@ Then run the following darcs commands to generate a darcs patch file named `WHAT
 
 ```
   darcs record
-  darcs send -o WHAT.darcs.patch
+  darcs send -o WHAT.darcs.patch http://tahoe-lafs.org/source/tahoe-lafs/trunk
 ```
 
 (The name of the file, which is given here as `WHAT.darcs.patch`, is not that important. Use a relevant word or two or maybe the ticket number.)