diff --git a/Data/Set/Extra.hs b/Data/Set/Extra.hs
--- a/Data/Set/Extra.hs
+++ b/Data/Set/Extra.hs
@@ -19,6 +19,7 @@
     , distrib
     , cartesianProduct
     , groupBy
+    , powerset
     , partitionM
     , unzip
     , gFind
@@ -103,6 +104,13 @@
 
 groupBy :: (Ord a, Ord b) => (a -> b) -> Set a -> Map.Map b (Set a)
 groupBy f xs = fold (\ x m -> Map.insertWith union (f x) (singleton x) m) Map.empty xs
+
+powerset :: Ord a => Set a -> Set (Set a)
+powerset s
+    | s == Set.empty = singleton Set.empty
+    | otherwise = Set.map (insert x) pxs `union` pxs
+        where (x, xs) = deleteFindMin s
+              pxs = powerset xs
 
 partitionM :: (Monad m, Ord a) => (a -> m Bool) -> Set a -> m (Set a, Set a)
 partitionM p xs =
diff --git a/set-extra.cabal b/set-extra.cabal
--- a/set-extra.cabal
+++ b/set-extra.cabal
@@ -1,5 +1,5 @@
 Name:           set-extra
-Version:        1.3.2
+Version:        1.4
 License:        BSD3
 License-File:	COPYING
 Author:         David Fox