diff --git a/.changeset/fair-worms-joke.md b/.changeset/fair-worms-joke.md
new file mode 100644
index 00000000000..59a9c014a1f
--- /dev/null
+++ b/.changeset/fair-worms-joke.md
@@ -0,0 +1,5 @@
+---
+"@clerk/backend": patch
+---
+
+Add missing `slug` property in TS type declaration for SMS webhook events
diff --git a/packages/backend/src/api/resources/JSON.ts b/packages/backend/src/api/resources/JSON.ts
index 8c07743905d..ddba80f514e 100644
--- a/packages/backend/src/api/resources/JSON.ts
+++ b/packages/backend/src/api/resources/JSON.ts
@@ -272,6 +272,7 @@ export interface SMSMessageJSON extends ClerkResourceJSON {
   user_id?: string;
   message: string;
   status: string;
+  slug?: string | null;
   data?: Record<string, any> | null;
   delivered_by_clerk: boolean;
 }