diff --git a/specification/_types/Binary.ts b/specification/_types/Binary.ts
index 8bc826754b..56b792ea38 100644
--- a/specification/_types/Binary.ts
+++ b/specification/_types/Binary.ts
@@ -19,3 +19,6 @@
 
 // Vector tile response
 export type MapboxVectorTiles = ArrayBuffer
+
+// ES|QL columns
+export type EsqlColumns = ArrayBuffer
diff --git a/specification/esql/query/QueryResponse.ts b/specification/esql/query/QueryResponse.ts
index dc29806ec0..25f71b15be 100644
--- a/specification/esql/query/QueryResponse.ts
+++ b/specification/esql/query/QueryResponse.ts
@@ -17,6 +17,8 @@
  * under the License.
  */
 
+import { EsqlColumns } from '@_types/Binary'
+
 export class Response {
-  body: ArrayBuffer
+  body: EsqlColumns
 }