diff --git a/buildstream/_message.py b/buildstream/_message.py
index 33f821f967521a95b9f53698a32b1d2c2cae212e..55c0f05b55a972876117e834bd8b5317743aa25b 100644
--- a/buildstream/_message.py
+++ b/buildstream/_message.py
@@ -76,7 +76,7 @@ class Message():
         self.task_id = task_id            # The plugin object ID of the task
         self.scheduler = scheduler        # Whether this is a scheduler level message
         self.creation_time = datetime.datetime.now()
-        if message_type in (MessageType.SUCCESS, MessageType.FAIL):
+        if message_type in (MessageType.SUCCESS, MessageType.FAIL, MessageType.SKIPPED):
             assert elapsed is not None
         # logfile should always be associated with these messages
         if message_type in (MessageType.START, MessageType.SUCCESS, MessageType.FAIL, MessageType.SKIPPED):