diff --git a/design/acme-orders-challenges-crd.md b/design/acme-orders-challenges-crd.md
index 5832dc641..53f9d84a6 100644
--- a/design/acme-orders-challenges-crd.md
+++ b/design/acme-orders-challenges-crd.md
@@ -467,6 +467,6 @@ in-progress orders that have been cancelled properly.
 
 This becomes difficult to manage effectively, and especially test.
 
-It is also very difficult to handle effective rate limitting when using this
+It is also very difficult to handle effective rate limiting when using this
 strategy, as it will mean even more code going into the `Prepare` function of
 the ACME issuer.