diff --git a/lenskit/lenskit/data/dataset.py b/lenskit/lenskit/data/dataset.py
index 28f07eae3..629f26f42 100644
--- a/lenskit/lenskit/data/dataset.py
+++ b/lenskit/lenskit/data/dataset.py
@@ -109,8 +109,8 @@ def user_count(self):
     @overload
     def user_id(self, users: int) -> Any: ...
     @overload
-    def user_id(self, users: NDArray[np.integer]) -> pd.Series[Any]: ...
-    def user_id(self, users: int | NDArray[np.integer]) -> Any:
+    def user_id(self, users: list[int] | NDArray[np.integer]) -> pd.Series[Any]: ...
+    def user_id(self, users: int | list[int] | NDArray[np.integer]) -> Any:
         """
         Look up the user ID for a given user number.  When passed a single
         number, it returns single identifier; when given an array of numbers, it
@@ -161,8 +161,8 @@ def user_num(
     @overload
     def item_id(self, items: int) -> Any: ...
     @overload
-    def item_id(self, items: NDArray[np.integer]) -> pd.Series[Any]: ...
-    def item_id(self, items: int | NDArray[np.integer]) -> Any:
+    def item_id(self, items: list[int] | NDArray[np.integer]) -> pd.Series[Any]: ...
+    def item_id(self, items: int | list[int] | NDArray[np.integer]) -> Any:
         """
         Look up the item ID for a given item number.  When passed a single
         number, it returns single identifier; when given an array of numbers, it
@@ -494,7 +494,7 @@ def id_counts(items: ArrayLike) -> pd.Series[np.dtype[np.int64]]:
     return pd.Series(counts, index=ids)
 
 
-def _lookup_id(index: pd.Index, nums: int | NDArray[np.integer]) -> Any:
+def _lookup_id(index: pd.Index, nums: int | list[int] | NDArray[np.integer]) -> Any:
     if np.isscalar(nums):
         nums = cast(int, nums)  # make the type checker shut up
         if nums < 0 or nums >= len(index):