diff --git a/api/v1/swagger/definitions/basket.yaml b/api/v1/swagger/definitions/basket.yaml
index 5b02068190..af08323abd 100644
--- a/api/v1/swagger/definitions/basket.yaml
+++ b/api/v1/swagger/definitions/basket.yaml
@@ -84,4 +84,9 @@ properties:
       - null
     description: "When items should be created for orders in this basket (Options:
       'ordering', 'receiving', 'cataloguing'. Null means system wide config)"
+  late_since_days:
+    type:
+      - integer
+      - "null"
+    description: The number of days the basket is late (x-koha-embed)
 additionalProperties: false
diff --git a/api/v1/swagger/paths/acquisitions_baskets.yaml b/api/v1/swagger/paths/acquisitions_baskets.yaml
index 30a6c6e2e6..c0fca2b2c4 100644
--- a/api/v1/swagger/paths/acquisitions_baskets.yaml
+++ b/api/v1/swagger/paths/acquisitions_baskets.yaml
@@ -14,6 +14,16 @@
       - $ref: "../swagger.yaml#/parameters/per_page"
       - $ref: "../swagger.yaml#/parameters/q_param"
       - $ref: "../swagger.yaml#/parameters/q_body"
+      - name: x-koha-embed
+        in: header
+        required: false
+        description: Embed list sent as a request header
+        type: array
+        items:
+          type: string
+          enum:
+            - late_since_days
+        collectionFormat: csv
     produces:
       - application/json
     responses:
diff --git a/api/v1/swagger/paths/acquisitions_orders.yaml b/api/v1/swagger/paths/acquisitions_orders.yaml
index 804fd9a4b2..5b87bf4cc3 100644
--- a/api/v1/swagger/paths/acquisitions_orders.yaml
+++ b/api/v1/swagger/paths/acquisitions_orders.yaml
@@ -53,6 +53,7 @@
             - basket
             - basket.basket_group
             - basket.creator
+            - basket.late_since_days
             - biblio
             - biblio.uncancelled_orders+count
             - biblio.holds+count
@@ -180,6 +181,7 @@
             - basket
             - basket.basket_group
             - basket.creator
+            - basket.late_since_days
             - biblio
             - biblio.uncancelled_orders+count
             - biblio.holds+count