diff --git a/apis/debug/data_column_sidecars.yaml b/apis/debug/data_column_sidecars.yaml
index f4b0976d..8895edc7 100644
--- a/apis/debug/data_column_sidecars.yaml
+++ b/apis/debug/data_column_sidecars.yaml
@@ -50,7 +50,7 @@ get:
                   - $ref: "../../beacon-node-oapi.yaml#/components/schemas/Fulu.DataColumnSidecars"
         application/octet-stream:
           schema:
-            description: "SSZ serialized `DataColumnSidecars` bytes. Use Accept header to choose this response type"
+            description: "SSZ serialized `List[DataColumnSidecar, NUMBER_OF_COLUMNS]` bytes. Use Accept header to choose this response type"
     "400":
       description: "The block ID supplied could not be parsed"
       content: