diff --git a/klient/play.py b/klient/play.py
index 4b12aba..5ebbbd7 100755
--- a/klient/play.py
+++ b/klient/play.py
@@ -1,18 +1,18 @@
 #!/usr/bin/env python3
 from __future__ import annotations
-from enum import Enum
 from typing import Callable, Iterable, Optional, List, Set
 import collections
+import enum
 import json
 import sys
 
 
-class Action(Enum):
-    UP = "up"
-    DOWN = "down"
-    LEFT = "left"
-    RIGHT = "right"
-    STAY = None
+class Action(enum.Enum):
+    UP = enum.auto()
+    DOWN = enum.auto()
+    LEFT = enum.auto()
+    RIGHT = enum.auto()
+    STAY = enum.auto()
 
     def invert(self) -> Action:
         if self == Action.UP:
@@ -25,6 +25,11 @@ class Action(Enum):
             return Action.LEFT
         return Action.STAY
 
+    def to_json(self) -> Optional[str]:
+        if self == Action.STAY:
+            return None
+        return self.name.lower()
+
 
 class State:
     def __init__(self, state: dict) -> None:
@@ -157,7 +162,7 @@ def pathfind(member: Member, goal: Field) -> Action:
 def build_turn(members: Iterable[Member]) -> dict:
     return {
         "members": [
-            {"id": member.id, "action": member.action}
+            {"id": member.id, "action": member.action.to_json()}
             for member in members
         ]
     }