diff --git a/System/Console/ParseArgs.hs b/System/Console/ParseArgs.hs
--- a/System/Console/ParseArgs.hs
+++ b/System/Console/ParseArgs.hs
@@ -303,10 +303,10 @@
                                    (show k))
 
 -- |Make a keymap for looking up a flag argument.
-make_keymap :: (Ord a, Ord k, Show k) =>
-               ((Arg a) -> Maybe k)   -- ^Mapping from argdesc to flag key.
-            -> [ Arg a ]              -- ^List of argdesc.
-            -> (Map.Map k (Arg a))    -- ^Map from key to argdesc.
+make_keymap :: (Ord k, Show k) =>
+               (Arg a -> Maybe k)   -- ^Mapping from argdesc to flag key.
+            -> [Arg a]              -- ^List of argdesc.
+            -> Map.Map k (Arg a)    -- ^Map from key to argdesc.
 make_keymap f_field ads =
     (keymap_from_list .
      filter_keys .
diff --git a/parseargs.cabal b/parseargs.cabal
--- a/parseargs.cabal
+++ b/parseargs.cabal
@@ -6,7 +6,7 @@
 Build-Type: Simple
 Description: Parse command-line arguments
 -- Don't forget to bump the source-repository this below
-Version: 0.2.0.7
+Version: 0.2.0.8
 Cabal-Version: >= 1.8
 License: BSD3
 License-File: COPYING
@@ -42,4 +42,4 @@
 Source-repository this
   Type:     git
   Location: git://github.com/BartMassey/parseargs.git
-  Tag:      v0.2.0.7
+  Tag:      v0.2.0.8