diff --git a/Data/Function/Tools.hs b/Data/Function/Tools.hs
--- a/Data/Function/Tools.hs
+++ b/Data/Function/Tools.hs
@@ -1,5 +1,6 @@
 module Data.Function.Tools (
   const2
+, const3
 , applyWhen
 , applyUnless
 , apply2way
@@ -11,6 +12,9 @@
 
 const2 :: a -> b -> c -> a
 const2 = const . const
+
+const3 :: a -> b -> c -> d -> a
+const3 = const . const . const
 
 applyWhen :: Bool -> (a -> a) -> a -> a
 applyWhen b f = if b then f else id
diff --git a/yjtools.cabal b/yjtools.cabal
--- a/yjtools.cabal
+++ b/yjtools.cabal
@@ -1,5 +1,5 @@
 Name:		yjtools
-Version:	0.9.15
+Version:	0.9.16
 Cabal-Version:	>= 1.2
 Build-Type:	Simple
 License:	LGPL