diff --git a/changelog.d/14087.doc b/changelog.d/14087.doc
new file mode 100644
index 000000000..28d1ce67c
--- /dev/null
+++ b/changelog.d/14087.doc
@@ -0,0 +1 @@
+The changelog entry ending in a full stop or exclamation mark is not optional.
diff --git a/docs/development/contributing_guide.md b/docs/development/contributing_guide.md
index 5c3722516..7f99220a3 100644
--- a/docs/development/contributing_guide.md
+++ b/docs/development/contributing_guide.md
@@ -390,7 +390,7 @@ This file will become part of our [changelog](
 https://github.com/matrix-org/synapse/blob/master/CHANGES.md) at the next
 release, so the content of the file should be a short description of your
 change in the same style as the rest of the changelog. The file can contain Markdown
-formatting, and should end with a full stop (.) or an exclamation mark (!) for
+formatting, and must end with a full stop (.) or an exclamation mark (!) for
 consistency.
 
 Adding credits to the changelog is encouraged, we value your