diff --git a/changelog.d/4-docs/group-id-docs b/changelog.d/4-docs/group-id-docs
new file mode 100644
index 0000000000..92249b035e
--- /dev/null
+++ b/changelog.d/4-docs/group-id-docs
@@ -0,0 +1 @@
+Update documentation of MLS group ID
diff --git a/libs/wire-api/src/Wire/API/Conversation/Protocol.hs b/libs/wire-api/src/Wire/API/Conversation/Protocol.hs
index 71a3fc1faf..321c106b6d 100644
--- a/libs/wire-api/src/Wire/API/Conversation/Protocol.hs
+++ b/libs/wire-api/src/Wire/API/Conversation/Protocol.hs
@@ -75,7 +75,7 @@ mlsDataSchema =
     <$> cnvmlsGroupId
       .= fieldWithDocModifier
         "group_id"
-        (description ?~ "An MLS group identifier (at most 256 bytes long)")
+        (description ?~ "A base64-encoded MLS group ID")
         schema
     <*> cnvmlsEpoch
       .= fieldWithDocModifier