diff --git a/digestive-functors.cabal b/digestive-functors.cabal
--- a/digestive-functors.cabal
+++ b/digestive-functors.cabal
@@ -1,5 +1,5 @@
 Name:     digestive-functors
-Version:  0.3.0.1
+Version:  0.3.0.2
 Synopsis: A practical formlet library
 
 Description:
diff --git a/src/Text/Digestive/Form/Internal.hs b/src/Text/Digestive/Form/Internal.hs
--- a/src/Text/Digestive/Form/Internal.hs
+++ b/src/Text/Digestive/Form/Internal.hs
@@ -141,6 +141,8 @@
 
 eval' context method env form = case form of
 
+    Pure Nothing (Singleton x) -> return (pure x, [])
+
     Pure Nothing _ ->
         error "No ref specified for field"