diff --git a/.spectral.yml b/.spectral.yml
index d13bc69..c12cf62 100644
--- a/.spectral.yml
+++ b/.spectral.yml
@@ -7,6 +7,7 @@ extends: [spectral:oas]
 
 functions:
   - requireExampleOrRef
+  - requireRequestBodyDescription
 
 rules:
   # =============================================================================
@@ -94,13 +95,12 @@ rules:
       function: requireExampleOrRef
 
   entur-request-body-description:
-    message: "Request bodies SHOULD have a description."
+    message: "Request bodies SHOULD have a description, either directly or on the referenced schema."
     documentationUrl: "https://github.com/entur/api-guidelines/blob/main/guidelines.md#21-general-design-principles"
     severity: warn
     given: $.paths.*.*.requestBody
     then:
-      field: description
-      function: truthy
+      function: requireRequestBodyDescription
 
   entur-response-body-examples:
     message: "Response bodies SHOULD include at least one example."
diff --git a/functions/requireRequestBodyDescription.js b/functions/requireRequestBodyDescription.js
new file mode 100644
index 0000000..c2b2864
--- /dev/null
+++ b/functions/requireRequestBodyDescription.js
@@ -0,0 +1,38 @@
+/**
+ * Custom Spectral function to check if a request body has a description,
+ * either directly on the requestBody or on the resolved schema reference.
+ */
+module.exports = (targetVal) => {
+  // Check if there's a direct description on the requestBody
+  if (targetVal.description) {
+    return;
+  }
+
+  // Check if the resolved schema has a description
+  if (targetVal.content) {
+    for (const [mediaTypeName, mediaType] of Object.entries(targetVal.content)) {
+      if (!mediaType.schema) {
+        return [{ message: `Request body SHOULD have a description, either directly or on the referenced schema. Media type "${mediaTypeName}" has no schema.` }];
+      }
+
+      const schema = mediaType.schema;
+
+      // Direct description on schema
+      if (schema.description) {
+        continue;
+      }
+
+      // Array schema with items that have a description
+      if (schema.type === 'array' && schema.items && schema.items.description) {
+        continue;
+      }
+
+      return [{ message: `Request body SHOULD have a description, either directly or on the referenced schema. Media type "${mediaTypeName}" is missing a description.` }];
+    }
+
+    // All media types have descriptions
+    return;
+  }
+
+  return [{ message: 'Request body SHOULD have a description, either directly or on the referenced schema.' }];
+};
\ No newline at end of file