diff --git a/seakale.cabal b/seakale.cabal
--- a/seakale.cabal
+++ b/seakale.cabal
@@ -1,5 +1,5 @@
 name:                  seakale
-version:               0.2.1.0
+version:               0.2.1.1
 synopsis:              Pure SQL layer on top of other libraries
 description:           This library allows you to write pure code doing operations on a SQL databases. It can therefore be tested by mocking the database with the package 'seakale-tests'. To run it of a specific database, you need another package such as 'seakale-postgresql'.
 license:               BSD3
@@ -14,7 +14,7 @@
 source-repository head
   type:                darcs
   location:            http://darcs.redspline.com/seakale
-  tag:                 0.2.1.0
+  tag:                 0.2.1.1
 
 library
   ghc-options:         -Wall
@@ -53,7 +53,7 @@
                        Database.Seakale.ToRow
                        Database.Seakale.Types
 
-  build-depends:       base >=4.8 && <4.10
+  build-depends:       base >=4.8 && <4.11
                      , free
                      , mtl
                      , bytestring
diff --git a/src/Database/Seakale/FromRow.hs b/src/Database/Seakale/FromRow.hs
--- a/src/Database/Seakale/FromRow.hs
+++ b/src/Database/Seakale/FromRow.hs
@@ -103,8 +103,9 @@
 class FromRow backend n a | a -> n where
   fromRow :: RowParser backend n a
 
-  default fromRow :: (Generic a, GFromRow backend ReadCon n (Rep a))
-                  => RowParser backend (n :+ Zero) a
+  default fromRow :: ( Generic a, GFromRow backend ReadCon n (Rep a)
+                     , n ~ (n :+ Zero) )
+                  => RowParser backend n a
   fromRow =
     gfromRow ReadCon Nothing `pbind` \case
       Nothing -> pfail "GFromRow backend ?: error while parsing"