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
@@ -80,6 +80,10 @@
 const tEmail: TRegex = tRegex(validEmailRegex);
 const tOldValidUsername: TRegex = tRegex(oldValidUsernameRegex);
 const tID: TRefinement<string> = t.refinement(t.String, (id: string) => !!id);
+const tUserID: TRefinement<string> = t.refinement(
+  t.String,
+  (id: string) => !!id,
+);
 
 const tMediaMessagePhoto: TInterface<PhotoMessageServerDBContent> = tShape({
   type: tString('photo'),
@@ -132,6 +136,7 @@
   tEmail,
   tOldValidUsername,
   tID,
+  tUserID,
   tMediaMessagePhoto,
   tMediaMessageVideo,
   tMediaMessageMedia,