diff --git a/20.md b/20.md
index 49e2396a..7e97dd91 100644
--- a/20.md
+++ b/20.md
@@ -82,7 +82,7 @@ Client Handling
 
 For the `pow:` prefix it may query relay metadata to get the updated difficulty requirement and try again in the background.
 
-For the `invalid:` and `blocked`: prefix the client may wish to show these as styled error popups.
+For the `invalid:` and `blocked:` prefix the client may wish to show these as styled error popups.
 
 The prefixes include a colon so that the message can be cleanly separated from the prefix by taking everything after `:` and trimming it.