diff --git a/slate/slate.py b/slate/slate.py
index 3a0e1ae..ca811ae 100644
--- a/slate/slate.py
+++ b/slate/slate.py
@@ -41,6 +41,7 @@ class Slate():
         }
         self.runners.update(runners)
         self._version = False
+        self.sweep_id = None
 
     def load_config(self, filename, name):
         config, stack = self._load_config(filename, name)