diff --git a/banzai/main.py b/banzai/main.py
index 115123da..e0fc4e66 100755
--- a/banzai/main.py
+++ b/banzai/main.py
@@ -48,13 +48,12 @@ def get_consumers(self, Consumer, channel):
 
     def on_message(self, body, message):
         instrument = LCOFrameFactory.get_instrument_from_header(body, self.runtime_context.db_address)
-        queue_name = self.runtime_context.CELERY_TASK_QUEUE_NAME
-        try:
-            if instrument.nx * instrument.ny > self.runtime_context.LARGE_WORKER_THRESHOLD:
-                queue_name = self.runtime_context.LARGE_WORKER_QUEUE
-        except Exception as e:
-            logger.warning(f"Instrument not found in DB, or instrument size not defined: {e}", extra_tags={'instrument': body.get('INSTRUME')})
-
+        if instrument is None or instrument.nx is None:
+            queue_name = self.runtime_context.CELERY_TASK_QUEUE_NAME
+        elif instrument.nx * instrument.ny > self.runtime_context.LARGE_WORKER_THRESHOLD:
+            queue_name = self.runtime_context.LARGE_WORKER_QUEUE
+        else:
+            queue_name = self.runtime_context.CELERY_TASK_QUEUE_NAME
         process_image.apply_async(args=(body, vars(self.runtime_context)),
                                   queue=queue_name)
         message.ack()  # acknowledge to the sender we got this message (it can be popped)