diff --git a/src/eventhandler.cpp b/src/eventhandler.cpp
index 4b26411d7..e3b84951c 100644
--- a/src/eventhandler.cpp
+++ b/src/eventhandler.cpp
@@ -1038,7 +1038,11 @@ QString EventHandler::getReadMarkersString() const
     QString readMarkersString = i18np("1 user: ", "%1 users: ", userIds.size());
     for (const auto &userId : userIds) {
         auto user = m_room->user(userId);
-        readMarkersString += user->displayname(m_room) + i18nc("list separator", ", ");
+        auto displayName = user->displayname(m_room);
+        if (displayName.isEmpty()) {
+            displayName = userId;
+        }
+        readMarkersString += displayName + i18nc("list separator", ", ");
     }
     readMarkersString.chop(2);
     return readMarkersString;
diff --git a/src/models/reactionmodel.cpp b/src/models/reactionmodel.cpp
index 157dc3d03..9c9b3f5f7 100644
--- a/src/models/reactionmodel.cpp
+++ b/src/models/reactionmodel.cpp
@@ -68,7 +68,8 @@ QVariant ReactionModel::data(const QModelIndex &index, int role) const
                     text += i18nc("Separate the usernames of users", " and ");
                 }
             }
-            text += reaction.authors.at(i).toMap()[QStringLiteral("displayName")].toString();
+            auto displayName = reaction.authors.at(i).toMap()[QStringLiteral("displayName")].toString();
+            text += displayName.isEmpty() ? reaction.authors.at(i).toMap()[QStringLiteral("id")].toString() : displayName;
         }
 
         if (reaction.authors.count() > 3) {