diff --git a/src/r0/message/create_message_event.rs b/src/r0/message/create_message_event.rs
index 671265ac..2a7a31b5 100644
--- a/src/r0/message/create_message_event.rs
+++ b/src/r0/message/create_message_event.rs
@@ -41,6 +41,8 @@ ruma_api! {
 
     response {
         /// A unique identifier for the event.
+        // This is not declared required in r0.6.0, but that was a bug that has now been fixed:
+        // https://github.com/matrix-org/matrix-doc/pull/2525
         pub event_id: EventId,
     }
 
diff --git a/src/r0/state/create_state_event_for_empty_key.rs b/src/r0/state/create_state_event_for_empty_key.rs
index 6c5b980f..1fe4083a 100644
--- a/src/r0/state/create_state_event_for_empty_key.rs
+++ b/src/r0/state/create_state_event_for_empty_key.rs
@@ -33,6 +33,8 @@ ruma_api! {
 
     response {
         /// A unique identifier for the event.
+        // This is not declared required in r0.6.0, but that was a bug that has now been fixed:
+        // https://github.com/matrix-org/matrix-doc/pull/2525
         pub event_id: EventId,
     }
 
diff --git a/src/r0/state/create_state_event_for_key.rs b/src/r0/state/create_state_event_for_key.rs
index 0754d72a..6f546666 100644
--- a/src/r0/state/create_state_event_for_key.rs
+++ b/src/r0/state/create_state_event_for_key.rs
@@ -37,6 +37,8 @@ ruma_api! {
 
     response {
         /// A unique identifier for the event.
+        // This is not declared required in r0.6.0, but that was a bug that has now been fixed:
+        // https://github.com/matrix-org/matrix-doc/pull/2525
         pub event_id: EventId,
     }