diff --git a/opentech/apply/workflow.py b/opentech/apply/workflow.py
index 5b0cbde8c0954fbf6aa55b54fdb70b302a7a2130..173156685ba691355edba24787820d60f9f72d93 100644
--- a/opentech/apply/workflow.py
+++ b/opentech/apply/workflow.py
@@ -1,5 +1,5 @@
 class Workflow:
-    def __init__(self, name, *stages):
+    def __init__(self, name: str, *stages: Stage) -> None:
         self.name = name
         if not stages:
             raise ValueError('Stages must be supplied')
@@ -7,5 +7,5 @@ class Workflow:
 
 
 class Stage:
-    def __init__(self, name):
+    def __init__(self, name: str) -> None:
         self.name = name