diff --git a/Data/Nat.hs b/Data/Nat.hs
--- a/Data/Nat.hs
+++ b/Data/Nat.hs
@@ -47,6 +47,15 @@
 natMul :: Nat -> Nat -> Nat
 natMul = (Data.Nat.*)
 
+{-| Converts a runtime 'Integer' to an existentially wrapped 'Nat'. Returns 'Nothing' if
+the argument is negative -}
+someNat :: Integer -> Maybe (SomeSing (KindOf Z))
+someNat n | n < 0 = Nothing
+someNat n = Just (go n) where  
+  go 0 = SomeSing SZ
+  go n = case go (n - 1) of
+    SomeSing sn -> SomeSing (SS sn)
+
 {-| Provides a shorthand for 'Nat'-s using "GHC.TypeLits", for example:
 
 >>> :kind! Lit 3
diff --git a/singleton-nats.cabal b/singleton-nats.cabal
--- a/singleton-nats.cabal
+++ b/singleton-nats.cabal
@@ -1,6 +1,6 @@
 
 name:                singleton-nats
-version:             0.3.0.1
+version:             0.3.1.0
 synopsis:            Unary natural numbers relying on the singletons infrastructure.         
 license:             BSD3
 license-file:        LICENSE