diff --git a/octue/cloud/pub_sub/message_handler.py b/octue/cloud/pub_sub/message_handler.py
index 8385539d7..296d35e47 100644
--- a/octue/cloud/pub_sub/message_handler.py
+++ b/octue/cloud/pub_sub/message_handler.py
@@ -273,6 +273,15 @@ def _extract_and_enqueue_event(self, message):
             self._child_sdk_version = attributes["version"]
 
         message_number = attributes["message_number"]
+
+        if message_number in self.waiting_messages:
+            logger.warning(
+                "%r: Message with duplicate message number %d received for question %s - overwriting original message.",
+                self.receiving_service,
+                message_number,
+                self.question_uuid,
+            )
+
         self.waiting_messages[message_number] = event
 
     def _attempt_to_handle_waiting_messages(self):
diff --git a/pyproject.toml b/pyproject.toml
index 24c706077..0aed7fb40 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "octue"
-version = "0.52.0"
+version = "0.52.1"
 description = "A package providing template applications for data services, and a python SDK to the Octue API."
 readme = "README.md"
 authors = ["Marcus Lugg <marcus@octue.com>", "Thomas Clark <support@octue.com>"]