diff --git a/src/main/java/eu/siacs/conversations/entities/Account.java b/src/main/java/eu/siacs/conversations/entities/Account.java
index dc354adc4a90e19639fe72a5fbbe069bf6a3967c..bfcee9597e66a45471802d315ce1a41eae69b1e8 100644
--- a/src/main/java/eu/siacs/conversations/entities/Account.java
+++ b/src/main/java/eu/siacs/conversations/entities/Account.java
@@ -488,7 +488,9 @@ public class Account extends AbstractEntity implements AvatarService.Avatarable
     }
 
     public Collection<Bookmark> getBookmarks() {
-        return this.bookmarks.values();
+        synchronized (this.bookmarks) {
+            return new HashSet<>(this.bookmarks.values());
+        }
     }
 
     public void setBookmarks(Map<Jid, Bookmark> bookmarks) {