diff --git a/api/advent22_api/routers/_misc.py b/api/advent22_api/routers/_misc.py
index 68a929e..3e099ae 100644
--- a/api/advent22_api/routers/_misc.py
+++ b/api/advent22_api/routers/_misc.py
@@ -15,9 +15,11 @@ from ._image import AdventImage
 ##########
 
 
-async def get_rnd(bonus_salt: Any = "") -> random.Random:
-    cfg = await get_config()
-    return random.Random(f"{cfg.puzzle.solution}{bonus_salt}")
+class Random(random.Random):
+    @classmethod
+    async def get(cls, bonus_salt: Any = "") -> "Random":
+        cfg = await get_config()
+        return cls(f"{cfg.puzzle.solution}{bonus_salt}")
 
 
 async def set_length(seq: Sequence, length: int) -> list:
@@ -29,8 +31,7 @@ async def set_length(seq: Sequence, length: int) -> list:
 
 async def shuffle(seq: Sequence, rnd: random.Random | None = None) -> list:
     # Zufallsgenerator
-    if rnd is None:
-        rnd = await get_rnd()
+    rnd = rnd or await Random.get()
 
     # Elemente mischen
     return rnd.sample(seq, len(seq))
@@ -89,7 +90,7 @@ async def get_auto_image(
 
     # hier niemals RuntimeError!
     image = await load_image(images[index])
-    rnd = await get_rnd(index)
+    rnd = await Random.get(index)
 
     # Buchstabe verstecken
     await image.hide_text(