diff --git a/atom-conduit.cabal b/atom-conduit.cabal
--- a/atom-conduit.cabal
+++ b/atom-conduit.cabal
@@ -1,6 +1,6 @@
 cabal-version: 2.2
 name: atom-conduit
-version: 0.8.0.0
+version: 0.9.0.0
 build-type: Simple
 license: CC0-1.0
 license-file: LICENSE
@@ -10,7 +10,7 @@
 synopsis: Streaming parser/renderer for the Atom 1.0 standard (RFC 4287).
 description: Cf README.
 category: XML, Conduit
-tested-with: GHC <8.10 && >=8.4.2
+tested-with: GHC <8.12 && >=8.4.2
 extra-source-files:
     README.md
 
@@ -46,7 +46,7 @@
         microlens-th,
         parsers,
         prettyprinter,
-        refined >=0.2,
+        refined >=0.5,
         safe-exceptions,
         text,
         time >=1.5,
@@ -66,7 +66,7 @@
         generic-random,
         QuickCheck,
         quickcheck-instances,
-        refined >=0.2,
+        refined >=0.5,
         tasty,
         tasty-quickcheck,
         time >=1.5,
@@ -102,7 +102,7 @@
         conduit >=1.3,
         data-default,
         microlens,
-        refined >=0.2,
+        refined >=0.5,
         resourcet,
         tasty,
         tasty-hunit,
diff --git a/src/Text/Atom/Types.hs b/src/Text/Atom/Types.hs
--- a/src/Text/Atom/Types.hs
+++ b/src/Text/Atom/Types.hs
@@ -49,7 +49,9 @@
 data Null deriving(Typeable)
 
 instance Predicate Null Text where
-  validate p value = unless (Text.null value) $ throwRefine $ RefineOtherException (typeOf p) $ "Text is not null: " <> pretty value
+  validate p value = if not $ Text.null value
+    then pure $ RefineOtherException (typeOf p) $ "Text is not null: " <> value
+    else Nothing
 
 data AtomURI = forall a . AtomURI (URIRef a)
 
diff --git a/test/QuickCheck.hs b/test/QuickCheck.hs
--- a/test/QuickCheck.hs
+++ b/test/QuickCheck.hs
@@ -3,12 +3,13 @@
 import           Control.Monad
 import           Data.Char
 import           Data.Conduit
-import           Data.Text                    as Text (Text, pack, null)
+import           Data.Text                    as Text (Text, null, pack)
 import           Data.Time.Clock
 import           Data.Void
 import           Data.XML.Types as XML
 import           Generic.Random
 import           Refined
+import           Refined.Unsafe (reallyUnsafeRefine)
 import           Test.QuickCheck.Instances
 import           Test.QuickCheck.Modifiers
 import           Test.Tasty
@@ -70,11 +71,6 @@
     return $ UTCTime d (fromIntegral (round s :: Int))
 
 
-instance Arbitrary (Refined (Not Null) Text) where
-  arbitrary = do
-    ~(Right text) <- refine <$> arbitrary `suchThat` (not . Text.null)
-    return text
-
 instance Arbitrary Scheme where
   arbitrary = do
     a <- getLetter <$> arbitrary
@@ -172,16 +168,19 @@
 mergeNodes (node:t) = node:mergeNodes t
 mergeNodes [] = []
 
+genNotNullText :: Gen (Refined (Not Null) Text)
+genNotNullText = reallyUnsafeRefine <$> arbitrary `suchThat` (not . Text.null)
+
 instance Arbitrary AtomText where
   arbitrary = genericArbitrary uniform
   shrink = genericShrink
 
 instance Arbitrary AtomPerson where
-  arbitrary = genericArbitrary uniform
+  arbitrary = AtomPerson <$> genNotNullText <*> arbitrary <*> arbitrary
   shrink = genericShrink
 
 instance Arbitrary AtomCategory where
-  arbitrary = genericArbitrary uniform
+  arbitrary = AtomCategory <$> genNotNullText <*> arbitrary <*> arbitrary
   shrink = genericShrink
 
 instance Arbitrary AtomLink where
@@ -189,7 +188,7 @@
   shrink = genericShrink
 
 instance Arbitrary AtomGenerator where
-  arbitrary = genericArbitrary uniform
+  arbitrary = AtomGenerator <$> arbitrary <*> arbitrary <*> genNotNullText
   shrink = genericShrink
 
 instance Arbitrary AtomSource where