diff --git a/lib/utils/validation-utils.js b/lib/utils/validation-utils.js
--- a/lib/utils/validation-utils.js
+++ b/lib/utils/validation-utils.js
@@ -1,6 +1,6 @@
 // @flow
 
-import t from 'tcomb';
+import t, { TUnion } from 'tcomb';
 import type {
   TStructProps,
   TIrreducible,
@@ -65,6 +65,22 @@
 const tOldValidUsername: TRegex = tRegex(oldValidUsernameRegex);
 const tID: TRefinement<string> = t.refinement(t.String, (id: string) => !!id);
 
+const tMediaMessagePhoto: TInterface = tShape({
+  type: tString('photo'),
+  uploadID: t.String,
+});
+
+const tMediaMessageVideo: TInterface = tShape({
+  type: tString('video'),
+  uploadID: t.String,
+  thumbnailUploadID: t.String,
+});
+
+const tMediaMessageMedia: TUnion<TInterface> = t.union([
+  tMediaMessagePhoto,
+  tMediaMessageVideo,
+]);
+
 export {
   tBool,
   tString,
@@ -82,4 +98,7 @@
   tEmail,
   tOldValidUsername,
   tID,
+  tMediaMessagePhoto,
+  tMediaMessageVideo,
+  tMediaMessageMedia,
 };