diff --git a/src/StringTable/AtomMap.hs b/src/StringTable/AtomMap.hs
--- a/src/StringTable/AtomMap.hs
+++ b/src/StringTable/AtomMap.hs
@@ -296,13 +296,13 @@
 update x y z = MkAtomMap (IM.update ( x) (fromAtom y) (fromAtomMap z))
 updateLookupWithKey ::  (Key -> a -> Maybe a) -> Key -> AtomMap a -> (Maybe a,AtomMap a)
 updateLookupWithKey x y z = (\(x, y) -> (x, MkAtomMap y)) (IM.updateLookupWithKey ((. unsafeIntToAtom) x) (fromAtom y) (fromAtomMap z))
-updateMax :: (a -> a) -> AtomMap a -> AtomMap a
-updateMax x y = MkAtomMap (IM.updateMax ( x) (fromAtomMap y))
-updateMaxWithKey :: (Key -> a -> a) -> AtomMap a -> AtomMap a
+updateMax :: (a -> Maybe a) -> AtomMap a -> AtomMap a
+updateMax x y = MkAtomMap (IM.updateMax (x) (fromAtomMap y))
+updateMaxWithKey :: (Key -> a -> Maybe a) -> AtomMap a -> AtomMap a
 updateMaxWithKey x y = MkAtomMap (IM.updateMaxWithKey ((. unsafeIntToAtom) x) (fromAtomMap y))
-updateMin :: (a -> a) -> AtomMap a -> AtomMap a
+updateMin :: (a -> Maybe a) -> AtomMap a -> AtomMap a
 updateMin x y = MkAtomMap (IM.updateMin ( x) (fromAtomMap y))
-updateMinWithKey :: (Key -> a -> a) -> AtomMap a -> AtomMap a
+updateMinWithKey :: (Key -> a -> Maybe a) -> AtomMap a -> AtomMap a
 updateMinWithKey x y = MkAtomMap (IM.updateMinWithKey ((. unsafeIntToAtom) x) (fromAtomMap y))
 updateWithKey ::  (Key -> a -> Maybe a) -> Key -> AtomMap a -> AtomMap a
 updateWithKey x y z = MkAtomMap (IM.updateWithKey ((. unsafeIntToAtom) x) (fromAtom y) (fromAtomMap z))
@@ -324,7 +324,7 @@
 deleteMax x = MkAtomMap (IM.deleteMax (fromAtomMap x))
 deleteMin :: AtomMap a -> AtomMap a
 deleteMin x = MkAtomMap (IM.deleteMin (fromAtomMap x))
-deleteFindMax :: AtomMap a -> (a, AtomMap a)
+deleteFindMax :: AtomMap a -> ((IM.Key, a), AtomMap a)
 deleteFindMax x = (\(x, y) -> (x, MkAtomMap y)) (IM.deleteFindMax (fromAtomMap x))
-deleteFindMin :: AtomMap a -> (a, AtomMap a)
+deleteFindMin :: AtomMap a -> ((IM.Key, a), AtomMap a)
 deleteFindMin x = (\(x, y) -> (x, MkAtomMap y)) (IM.deleteFindMin (fromAtomMap x))
diff --git a/stringtable-atom.cabal b/stringtable-atom.cabal
--- a/stringtable-atom.cabal
+++ b/stringtable-atom.cabal
@@ -1,5 +1,5 @@
 Name:                stringtable-atom
-Version:             0.0.6.1
+Version:             0.0.6.2
 Category:            Data, Pugs
 Synopsis:            Memoize Strings as Atoms for fast comparison and sorting, with maps and sets
 Description:         Memoize Strings as Atoms for fast comparison and sorting, with maps and sets