diff --git a/klient/play.py b/klient/play.py
index 576ad3e..b1667b9 100755
--- a/klient/play.py
+++ b/klient/play.py
@@ -14,20 +14,18 @@ class Action(enum.Enum):
     RIGHT = enum.auto()
     STAY = enum.auto()
 
+    _inversions = {
+        UP: DOWN,
+        DOWN: UP,
+        LEFT: RIGHT,
+        RIGHT: LEFT,
+        STAY: STAY,
+    }
+
     def invert(self) -> Action:
-        if self == Action.UP:
-            return Action.DOWN
-        if self == Action.DOWN:
-            return Action.UP
-        if self == Action.LEFT:
-            return Action.RIGHT
-        if self == Action.RIGHT:
-            return Action.LEFT
-        return Action.STAY
-
-    def to_json(self) -> Optional[str]:
-        if self == Action.STAY:
-            return None
+        return self._inversions[self]
+
+    def __str__(self) -> str:
         return self.name.lower()
 
 
@@ -165,7 +163,7 @@ def pathfind(member: Member, goal: Field) -> Action:
 def build_turn(members: Iterable[Member]) -> dict:
     return {
         "members": [
-            {"id": member.id, "action": member.action.to_json()}
+            {"id": member.id, "action": str(member.action)}
             for member in members
         ]
     }
diff --git a/server/hra/game.py b/server/hra/game.py
index d4e5bf1..c4358a1 100644
--- a/server/hra/game.py
+++ b/server/hra/game.py
@@ -27,7 +27,7 @@ class Logic:
 @add_logic
 class Occupy(Logic):
     MOVE_VECTORS = {
-        None: (0, 0),
+        "stay": (0, 0),
         "left": (0, -1),
         "right": (0, 1),
         "up": (-1, 0),