diff --git a/03.md b/03.md
index 0d8953c..152ec45 100644
--- a/03.md
+++ b/03.md
@@ -78,7 +78,7 @@ If successful, `Bob` will respond with a `PostSwapResponse`
 
 ## Cached Responses
 
-`Bob` **MUST** cache every successful `PostSwapResponse` using `PostSwapRequest` as key.
+`Bob` **MUST** cache every successful `PostSwapResponse` using `PostSwapRequest` as the key.
 Each cache entry has a TTL (Time-To-Live) of at least 1800 seconds.
 In the event of a network error, `Alice` **CAN** replay the same exact request and get the same response.