diff --git a/src/_zkapauthorizer/resource.py b/src/_zkapauthorizer/resource.py
index 79c8d3146e82c3d42b5c5a9f404ee8496eaafd85..b09b58ab672e5443a062e3cc68bd6ae8dfeec8ca 100644
--- a/src/_zkapauthorizer/resource.py
+++ b/src/_zkapauthorizer/resource.py
@@ -59,7 +59,7 @@ from .controller import (
 )
 
 # The number of tokens to submit with a voucher redemption.
-NUM_TOKENS = 512000
+NUM_TOKENS = 2 ** 15
 
 
 class IZKAPRoot(IResource):