diff --git a/src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java b/src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java
index 3f5e46ec5df0a8d22424276c9d6f8ee20e732a79..5ca7a135a19e701a6a4d1144ef8eafe4e06086b9 100644
--- a/src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java
+++ b/src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java
@@ -1421,7 +1421,8 @@ public class MessageAdapter extends ArrayAdapter<Message> {
         if (type == RECEIVED || type == SENT) {
             String subject = message.getSubject();
             if (subject == null && message.getThread() != null) {
-                subject = ((Conversation) message.getConversation()).getThread(message.getThread().getContent()).getSubject();
+                final var thread = ((Conversation) message.getConversation()).getThread(message.getThread().getContent());
+                if (thread != null) subject = thread.getSubject();
             }
             if (muted || subject == null) {
                 viewHolder.subject.setVisibility(View.GONE);