diff --git a/src/utils/encoding.js b/src/utils/encoding.js
index fe409a7b..eee22af7 100644
--- a/src/utils/encoding.js
+++ b/src/utils/encoding.js
@@ -599,7 +599,7 @@ export const writeDocumentStateVector = (encoder, doc) => writeStateVector(encod
  *
  * @param {Doc|Map<number,number>} doc
  * @param {IdSetEncoderV1 | IdSetEncoderV2} [encoder]
- * @return {Uint8Array}
+ * @return {Uint8Array<ArrayBuffer>}
  *
  * @function
  */
@@ -616,7 +616,7 @@ export const encodeStateVectorV2 = (doc, encoder = new IdSetEncoderV2()) => {
  * Encode State as Uint8Array.
  *
  * @param {Doc|Map<number,number>} doc
- * @return {Uint8Array}
+ * @return {Uint8Array<ArrayBuffer>}
  *
  * @function
  */
diff --git a/src/utils/updates.js b/src/utils/updates.js
index 5dcd227a..6cb15713 100644
--- a/src/utils/updates.js
+++ b/src/utils/updates.js
@@ -500,7 +500,7 @@ export const diffUpdateV2 = (update, sv, YDecoder = UpdateDecoderV2, YEncoder =
  * @deprecated
  * @todo remove this in favor of intersectupdate
  *
- * @param {Uint8Array} update
+ * @param {Uint8Array<ArrayBuffer>} update
  * @param {Uint8Array<ArrayBuffer>} sv
  */
 export const diffUpdate = (update, sv) => diffUpdateV2(update, sv, UpdateDecoderV1, UpdateEncoderV1)
diff --git a/tests/updates.tests.js b/tests/updates.tests.js
index 3afaec8f..6817657d 100644
--- a/tests/updates.tests.js
+++ b/tests/updates.tests.js
@@ -15,11 +15,11 @@ import * as array from 'lib0/array'
  * @property {function(Y.Doc, Uint8Array):void} Enc.applyUpdate
  * @property {function(Uint8Array):void} Enc.logUpdate
  * @property {function(Uint8Array):{deletes:Y.IdSet,inserts:Y.IdSet}} Enc.readUpdateToContentIds
- * @property {function(Y.Doc):Uint8Array} Enc.encodeStateVector
- * @property {function(Uint8Array):Uint8Array} Enc.encodeStateVectorFromUpdate
+ * @property {function(Y.Doc):Uint8Array<ArrayBuffer>} Enc.encodeStateVector
+ * @property {function(Uint8Array):Uint8Array<ArrayBuffer>} Enc.encodeStateVectorFromUpdate
  * @property {'update'|'updateV2'} Enc.updateEventName
  * @property {string} Enc.description
- * @property {function(Uint8Array, Uint8Array):Uint8Array} Enc.diffUpdate
+ * @property {function(Uint8Array<ArrayBuffer>, Uint8Array<ArrayBuffer>):Uint8Array<ArrayBuffer>} Enc.diffUpdate
  */
 
 /**