diff --git a/islpy/__init__.py b/islpy/__init__.py
index a048aea..316daf2 100644
--- a/islpy/__init__.py
+++ b/islpy/__init__.py
@@ -475,14 +475,12 @@ def affs_from_space(space: Space) -> dict[Literal[0] | str, PwAff]:
     "UnionMapList",
     "UnionPwAff",
     "UnionPwAffList",
-    "UnionPwAffList",
     "UnionPwMultiAff",
     "UnionPwMultiAffList",
     "UnionPwQPolynomial",
     "UnionPwQPolynomialFold",
     "UnionSet",
     "UnionSetList",
-    "UnionSetList",
     "Val",
     "ValList",
     "Vec",