diff --git a/lib/shared/avatar-utils.js b/lib/shared/avatar-utils.js
--- a/lib/shared/avatar-utils.js
+++ b/lib/shared/avatar-utils.js
@@ -259,16 +259,18 @@
   };
 }
 
-function getAvatarForUser(user: ?GenericUserInfoWithAvatar): ClientAvatar {
-  if (user?.avatar) {
-    return user.avatar;
+function getAvatarForUser(
+  usernameAndAvatar: ?{ +username?: ?string, +avatar?: ?ClientAvatar, ... },
+): ClientAvatar {
+  if (usernameAndAvatar?.avatar) {
+    return usernameAndAvatar.avatar;
   }
 
-  if (!user?.username) {
+  if (!usernameAndAvatar?.username) {
     return defaultAnonymousUserEmojiAvatar;
   }
 
-  return getDefaultAvatar(user.username);
+  return getDefaultAvatar(usernameAndAvatar.username);
 }
 
 function getUserAvatarForThread(