diff --git a/src/edu/stanford/bmir/protege/web/server/notes/OWLAPINotesManagerNotesAPIImpl.java b/src/edu/stanford/bmir/protege/web/server/notes/OWLAPINotesManagerNotesAPIImpl.java
index 954795cf40..7641df24e0 100644
--- a/src/edu/stanford/bmir/protege/web/server/notes/OWLAPINotesManagerNotesAPIImpl.java
+++ b/src/edu/stanford/bmir/protege/web/server/notes/OWLAPINotesManagerNotesAPIImpl.java
@@ -226,8 +226,11 @@ private AnnotatableThing getAnnotatableThingForObjectId(NoteId noteId) {
 
     @Override
     public void deleteNoteAndReplies(NoteId noteId) {
-        notesManager.deleteNote(noteId.getLexicalForm());
-        project.getEventManager().postEvent(new NoteDeletedEvent(project.getProjectId(), noteId));
+        Annotation note = notesManager.getNote(noteId.getLexicalForm());
+        if (note != null) {
+            notesManager.deleteNote(noteId.getLexicalForm());
+            project.getEventManager().postEvent(new NoteDeletedEvent(project.getProjectId(), noteId));
+        }
     }