diff --git a/Text/Reform/Core.hs b/Text/Reform/Core.hs
--- a/Text/Reform/Core.hs
+++ b/Text/Reform/Core.hs
@@ -98,6 +98,7 @@
                  (Found x, Found y) -> return $ Found (x SG.<> y)
                  (Found x, _      ) -> return $ Found x
                  (_      , Found y) -> return $ Found y
+                 (Default, Default) -> return Default
 
 -- | Not quite sure when this is useful and so hard to say if the rules for combining things with Missing/Default are correct
 instance (SG.Semigroup input, Monad m) => Monoid (Environment m input) where
diff --git a/Text/Reform/Generalized.hs b/Text/Reform/Generalized.hs
--- a/Text/Reform/Generalized.hs
+++ b/Text/Reform/Generalized.hs
@@ -41,6 +41,7 @@
                     return ( View $ const $ toView i initialValue
                            , return $ Error [(unitRange i, error)]
                            )
+                (Found fromInput) -> error "input: How could this even happen?"
                 Missing ->
                     return ( View $ const $ toView i initialValue
                            , return $ Error [(unitRange i, commonFormError (InputMissing i))]
@@ -306,6 +307,7 @@
 
       selectFirst :: [(Form m input error view proof a, lbl)] -> [(Form m input error view proof a, lbl, Bool)]
       selectFirst ((frm, lbl):fs) = (frm,lbl,True) : map (\(frm',lbl') -> (frm', lbl', False)) fs
+      selectFirst [] = []
 
       markSelected :: Int -> [(Int, (Form m input error view proof a, lbl))] -> [(Form m input error view proof a, lbl, Bool)]
       markSelected n choices =
diff --git a/reform.cabal b/reform.cabal
--- a/reform.cabal
+++ b/reform.cabal
@@ -1,5 +1,5 @@
 Name:                reform
-Version:             0.2.7.5
+Version:             0.2.7.6
 Synopsis:            reform is a type-safe HTML form generation and validation library
 Description:         reform follows in the footsteps of formlets and
                      digestive-functors <= 0.2. It provides a
@@ -14,7 +14,7 @@
 Build-type:          Simple
 Homepage:            http://www.happstack.com/
 Cabal-version:       >=1.10
-tested-with:         GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.4, GHC == 8.6.5, GHC == 8.8.4, GHC == 8.10.7, GHC == 9.0.2, GHC == 9.2.2
+tested-with:         GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.4, GHC == 8.6.5, GHC == 8.8.4, GHC == 8.10.7, GHC == 9.0.2, GHC == 9.2.8, GHC == 9.4.8, GHC == 9.6.7, GHC == 9.8.4, GHC == 9.10.2, GHC == 9.12.2, GHC == 9.14.1
 
 source-repository head
     type:     git
@@ -30,8 +30,8 @@
                        Text.Reform.Proof
                        Text.Reform.Result
   Build-depends:       base             >= 4    && < 5,
-                       containers       >= 0.4  && < 0.7,
-                       mtl              >= 2.0  && < 2.3,
+                       containers       >= 0.4  && < 0.9,
+                       mtl              >= 2.0  && < 2.4,
                        semigroups       >= 0.16 && < 0.21,
-                       text             >= 0.11 && < 2.1
+                       text             >= 0.11 && < 2.2