diff --git a/changelogs/client_server/newsfragments/3127.clarification b/changelogs/client_server/newsfragments/3127.clarification
new file mode 100644
index 00000000..d858e2b7
--- /dev/null
+++ b/changelogs/client_server/newsfragments/3127.clarification
@@ -0,0 +1 @@
+Fix the maximum event size restriction (65535 bytes -> 65536).
diff --git a/content/client-server-api/_index.md b/content/client-server-api/_index.md
index ed4d0399..a5964fe7 100644
--- a/content/client-server-api/_index.md
+++ b/content/client-server-api/_index.md
@@ -1447,7 +1447,7 @@ following fields.
 
 ### Size limits
 
-The complete event MUST NOT be larger than 65535 bytes, when formatted
+The complete event MUST NOT be larger than 65536 bytes, when formatted
 as a [PDU for the Server-Server
 protocol](/server-server-api/#pdus), including any
 signatures, and encoded as [Canonical
@@ -1463,7 +1463,7 @@ There are additional restrictions on sizes per key:
 
 Some event types have additional size restrictions which are specified
 in the description of the event. Additional keys have no limit other
-than that implied by the total 65 KB limit on events.
+than that implied by the total 64 KiB limit on events.
 
 ### Room Events