diff --git a/changelogs/client_server/newsfragments/3332.clarification b/changelogs/client_server/newsfragments/3332.clarification
new file mode 100644
index 00000000..63e54ba6
--- /dev/null
+++ b/changelogs/client_server/newsfragments/3332.clarification
@@ -0,0 +1 @@
+Clarify that all request bodies are required.
diff --git a/data/api/client-server/cross_signing.yaml b/data/api/client-server/cross_signing.yaml
index c4c4d10f..47ab4da2 100644
--- a/data/api/client-server/cross_signing.yaml
+++ b/data/api/client-server/cross_signing.yaml
@@ -42,6 +42,7 @@ paths:
           name: keys
           description: |-
             The keys to be published.
+          required: true
           schema:
             type: object
             properties:
@@ -149,6 +150,7 @@ paths:
           name: signatures
           description: |-
             The signatures to be published.
+          required: true
           schema:
             type: object
             title: Signatures