diff --git a/Database/Narc.hs b/Database/Narc.hs
--- a/Database/Narc.hs
+++ b/Database/Narc.hs
@@ -17,7 +17,7 @@
   -- * Translation to an SQL representation
   narcToSQL, narcToSQLString,
   -- * The language itself
-  unit, table, cnst, primApp, abs, app, ifthenelse, singleton,
+  unit, table, cnst, Constable, primApp, abs, app, ifthenelse, singleton,
   nil, union, record, project, foreach, having,
   Type(..)
 ) where
@@ -93,9 +93,11 @@
 unit = return $ (!) Unit
 
 -- | A polymorphic way of embedding constants into a term.
-class Const' a where cnst :: a -> NarcTerm
-instance Const' Bool where cnst b = return ((!)(Bool b))
-instance Const' Integer where cnst n = return ((!)(Num n))
+class Constable a where
+    -- | Lift a constant value into a query.
+    cnst :: a -> NarcTerm
+instance Constable Bool where cnst b = return ((!)(Bool b))
+instance Constable Integer where cnst n = return ((!)(Num n))
 
 -- | Apply some primitive function, such as @(+)@ or @avg@, to a list
 -- of arguments.
diff --git a/narc.cabal b/narc.cabal
--- a/narc.cabal
+++ b/narc.cabal
@@ -7,7 +7,7 @@
 -- The package version. See the Haskell package versioning policy
 -- (http://www.haskell.org/haskellwiki/Package_versioning_policy) for
 -- standards guiding when and how versions should be incremented.
-Version:             0.1.1
+Version:             0.1.2
 
 -- A short (one-line) description of the package.
 Synopsis:            Query SQL databases using Nested Relational Calculus embedded in Haskell.
@@ -66,7 +66,7 @@
   Exposed-modules:     Database.Narc, Database.Narc.SQL, Database.Narc.Test, Database.Narc.Type, Database.Narc.HDBC
   
   -- Packages needed in order to build this package.
-  Build-depends: base >=4 && < 4, HUnit, QuickCheck, mtl, random, HDBC
+  Build-depends: base >=4 && < 5, HUnit, QuickCheck, mtl, random, HDBC
   
   -- Modules not exported by this package.
   Other-modules:       Gensym, QCUtils, Database.Narc.TermGen, Database.Narc.Var, Database.Narc.Contract, Database.Narc.Debug, Database.Narc.TypeInfer, Database.Narc.Util, Database.Narc.AST.Pretty, Database.Narc.Failure.QuickCheck, Database.Narc.Rewrite, Database.Narc.AST, Database.Narc.Common, Database.Narc.Compile, Database.Narc.Eval, Database.Narc.Failure, Database.Narc.Pretty, Database.Narc.SQL.Pretty