diff --git a/ibis/expr/types/relations.py b/ibis/expr/types/relations.py
index a22871a74cfa1..50562d6f5a710 100644
--- a/ibis/expr/types/relations.py
+++ b/ibis/expr/types/relations.py
@@ -4268,7 +4268,7 @@ def pivot_wider(
         if isinstance(values_agg, str):
             values_agg = operator.methodcaller(values_agg)
         elif isinstance(values_agg, Deferred):
-            values_agg = lambda t: resolve(values_agg, _=t)
+            values_agg = lambda t, what=values_agg: resolve(what, _=t)
 
         if names is None:
             # no names provided, compute them from the data
diff --git a/ibis/selectors.py b/ibis/selectors.py
index ebb918c9badc6..a36e93181a93b 100644
--- a/ibis/selectors.py
+++ b/ibis/selectors.py
@@ -66,7 +66,6 @@
 import ibis.expr.operations as ops
 import ibis.expr.types as ir
 from ibis import util
-from ibis.common.collections import frozendict  # noqa: TCH001
 from ibis.common.selectors import All, Any, Expandable, Selector
 from ibis.common.typing import VarTuple  # noqa: TCH001
 
@@ -424,7 +423,7 @@ class Across(Expandable):
     funcs: Union[
         Builder,
         Callable[[ir.Value], ir.Value],
-        frozendict[Optional[str], Union[Builder, Callable[[ir.Value], ir.Value]]],
+        dict[Optional[str], Union[Builder, Callable[[ir.Value], ir.Value]]],
     ]
     names: Union[str, Callable[[str, Optional[str]], str]]