diff --git a/src/endpoints/forms.tsp b/src/endpoints/forms.tsp
index 9b5607d..2b7a938 100644
--- a/src/endpoints/forms.tsp
+++ b/src/endpoints/forms.tsp
@@ -343,7 +343,8 @@ namespace Forms {
             @path answerId: uint32,
 
             @path
-            message_id: uint32,
+            @format("uuid")
+            message_id: string,
 
             @body body: {
               body: string;
@@ -361,7 +362,8 @@ namespace Forms {
             @path answerId: uint32,
 
             @path
-            message_id: uint32,
+            @format("uuid")
+            message_id: string,
           ): {
             @statusCode statusCode: 204;
           } | {
diff --git a/src/models/message.tsp b/src/models/message.tsp
index 590badb..8070e64 100644
--- a/src/models/message.tsp
+++ b/src/models/message.tsp
@@ -1,6 +1,10 @@
 import "../endpoints/users.tsp";
 
 model Message {
+  @visibility("read")
+  @format("uuid")
+  id: string;
+
   body: string;
   sender: User;
   timestamp: utcDateTime;