diff --git a/workers/dockerfilebuild.py b/workers/dockerfilebuild.py
index 69ad05739..a4de1cc47 100644
--- a/workers/dockerfilebuild.py
+++ b/workers/dockerfilebuild.py
@@ -560,9 +560,10 @@ class DockerfileBuildWorker(Worker):
     try:
       build_dir = self._mime_processors[c_type](docker_resource)
     except Exception as ex:
-      log_appender(ex.message, build_logs.ERROR)
-      spawn_failure(ex.message, event_data)
-      raise JobException(ex.message)      
+      cur_message = ex.message or 'Error while unpacking build package'
+      log_appender(cur_message, build_logs.ERROR)
+      spawn_failure(cur_message, event_data)
+      raise JobException(cur_message)      
 
     # Start the build process.
     try: