diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1f74b745..ce8c78f1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - `sortBy` and `sortDirection` to `FormSearchOptions`
+- `emailClassificationId` to form schema
 
 ## [13.1.7] - 2026-06-18
 
diff --git a/src/lib/forms-schema/index.ts b/src/lib/forms-schema/index.ts
index f7d3e5b1..25d8259b 100644
--- a/src/lib/forms-schema/index.ts
+++ b/src/lib/forms-schema/index.ts
@@ -902,6 +902,7 @@ const formSchema = Joi.object().keys({
           .required(),
       }),
     ),
+  emailClassificationId: Joi.number().integer().min(1),
 })
 
 export const formEventTypes: SubmissionEventTypes.FormEventType[] = [