diff --git a/changelogs/client_server/newsfragments/1059.clarification b/changelogs/client_server/newsfragments/1059.clarification
new file mode 100644
index 00000000..2e94fb7f
--- /dev/null
+++ b/changelogs/client_server/newsfragments/1059.clarification
@@ -0,0 +1 @@
+Fix room state 400 code error examples to match known error codes.
diff --git a/data/api/client-server/room_state.yaml b/data/api/client-server/room_state.yaml
index 89792e63..d43bc802 100644
--- a/data/api/client-server/room_state.yaml
+++ b/data/api/client-server/room_state.yaml
@@ -114,7 +114,7 @@ paths:
 
             Some example error codes include:
 
-            * `M_INVALID_PARAMETER`: One or more aliases within the `m.room.canonical_alias`
+            * `M_INVALID_PARAM`: One or more aliases within the `m.room.canonical_alias`
               event have invalid syntax.
 
             * `M_BAD_ALIAS`: One or more aliases within the `m.room.canonical_alias` event