diff --git a/api/client-server/v2_alpha/definitions/error.yaml b/api/client-server/v2_alpha/definitions/error.yaml
new file mode 100644
index 00000000..20312ae4
--- /dev/null
+++ b/api/client-server/v2_alpha/definitions/error.yaml
@@ -0,0 +1,10 @@
+type: object
+description: A Matrix-level Error
+properties:
+  errcode:
+    type: string
+    description: An error code.
+  error:
+    type: string
+    description: A human-readable error message.
+required: ["errcode"]
\ No newline at end of file
diff --git a/api/client-server/v2_alpha/receipts.yaml b/api/client-server/v2_alpha/receipts.yaml
index 4ef435b0..b60f72e6 100644
--- a/api/client-server/v2_alpha/receipts.yaml
+++ b/api/client-server/v2_alpha/receipts.yaml
@@ -47,6 +47,7 @@ paths:
           required: true
           x-example: "$1924376522eioj:example.com"
         - in: body
+          name: receipt
           description: |-
             Extra receipt information to attach to ``content`` if any. The
             server will automatically set the ``ts`` field.
@@ -65,4 +66,4 @@ paths:
         429:
           description: This request was rate-limited.
           schema:
-            "$ref": "definitions/error.yaml"
\ No newline at end of file
+            "$ref": "definitions/error.yaml"