diff --git a/inline-r/src/Foreign/R/Internal.hs b/inline-r/src/Foreign/R/Internal.hs
index 0a00acda..8974f521 100644
--- a/inline-r/src/Foreign/R/Internal.hs
+++ b/inline-r/src/Foreign/R/Internal.hs
@@ -23,7 +23,6 @@ import Foreign.R.Context (SEXP0(..))
 import Control.Applicative
 import Control.DeepSeq (NFData(..))
 import Control.Monad.Primitive ( unsafeInlineIO )
-import Data.Singletons (fromSing)
 import Foreign (Ptr, Storable(..))
 import Foreign.C
 import Prelude hiding (asTypeOf, length)
@@ -75,9 +74,6 @@ cIntConv = fromIntegral
 cIntToEnum :: Enum a => CInt -> a
 cIntToEnum = toEnum . cIntConv
 
-cUIntFromSingEnum :: SSEXPTYPE a -> CUInt
-cUIntFromSingEnum = cIntConv . fromEnum . fromSing
-
 cIntFromEnum :: Enum a => a -> CInt
 cIntFromEnum = cIntConv . fromEnum
 
diff --git a/inline-r/src/Foreign/R/Type.hsc b/inline-r/src/Foreign/R/Type.hsc
index 00d98fef..2c333b21 100644
--- a/inline-r/src/Foreign/R/Type.hsc
+++ b/inline-r/src/Foreign/R/Type.hsc
@@ -24,17 +24,9 @@
 -- c2hs for discharging the boilerplate around 'SEXPTYPE'. This is because
 -- 'SEXPTYPE' is nearly but not quite a true enumeration and c2hs has trouble
 -- dealing with that.
---
--- This module also defines a singleton version of 'SEXPTYPE', called
--- 'SSEXPTYPE'. This is actually a family of types, one for each possible
--- 'SEXPTYPE'. Singleton types are a way of emulating dependent types in
--- a language that does not have true dependent type. They are useful in
--- functions whose result type depends on the value of one of its arguments. See
--- e.g. 'Foreign.R.allocVector'.
 
 module Foreign.R.Type
   ( SEXPTYPE(..)
-  , SSEXPTYPE(..)
   , Sing
   , Logical(..)
   , PairList
@@ -188,8 +180,6 @@ instance Enum ParseStatus where
     (#const PARSE_EOF)        -> PARSE_EOF
     _ -> error "ParseStatus.fromEnum: can't mach value"
 
-genSingletons [''SEXPTYPE]
-
 -- | Used where the R documentation speaks of "pairlists", which are really just
 -- regular lists.
 type PairList = List