diff --git a/tasks.py b/tasks.py
index 2832c4d2abf40b35cbcc47e38c4d9a4f74cbe642..a214a47c20384951ec182be6f375cf3a25dd28d1 100644
--- a/tasks.py
+++ b/tasks.py
@@ -95,6 +95,11 @@ def parse_protocol_async_inner(protocol, encoded_kwargs):
         db.session.add(error)
         db.session.commit()
         return
+    if protocol.source == config.EMPTY_ETHERPAD:
+        error = protocol.create_error("Parsing", "The etherpad is unmodified and does not contain a protocol.", protocol.source)
+        db.session.add(error)
+        db.session.commit()
+        return
     tree = None
     try:
         tree = parse(protocol.source)