diff --git a/api/advent22_api/routers/admin.py b/api/advent22_api/routers/admin.py
index e22c1f7..5edc8ab 100644
--- a/api/advent22_api/routers/admin.py
+++ b/api/advent22_api/routers/admin.py
@@ -25,7 +25,7 @@ class ConfigModel(BaseModel):
     class __Puzzle(BaseModel):
         solution: str
         first: date
-        next: date
+        next: date | None
         last: date
         end: date
         seed: str
diff --git a/ui/src/lib/api.ts b/ui/src/lib/api.ts
index f4f20c6..199172b 100644
--- a/ui/src/lib/api.ts
+++ b/ui/src/lib/api.ts
@@ -2,7 +2,7 @@ export interface ConfigModel {
   puzzle: {
     solution: string;
     first: string;
-    next: string;
+    next: string | null;
     last: string;
     end: string;
     seed: string;