diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+## 0.4.0.0
+### Changed
+- Switch from data-default-class to data-default. This is recommended by https://github.com/mauke/data-default/blob/ba1596728252c8f640d21225e728f508f2f3233c/Changes.pod#user-content-pod0.8.0.0
+
 ## 0.3.2.0
 ### Changed
 - Make widgetColumn function slightly more flexible.
diff --git a/examples/resizing-cells/Main.hs b/examples/resizing-cells/Main.hs
--- a/examples/resizing-cells/Main.hs
+++ b/examples/resizing-cells/Main.hs
@@ -2,7 +2,7 @@
 
 import Control.Concurrent (threadDelay)
 import Control.Monad (forM, forever)
-import Data.Default.Class (def)
+import Data.Default (def)
 import Data.Sequence (Seq)
 import qualified Data.Sequence as S
 import Data.Text (Text, pack, words)
diff --git a/monomer-hagrid.cabal b/monomer-hagrid.cabal
--- a/monomer-hagrid.cabal
+++ b/monomer-hagrid.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.0
 name:               monomer-hagrid
-version:            0.3.2.0
+version:            0.4.0.0
 license:            MIT
 license-file:       LICENSE
 maintainer:         garethdanielsmith@gmail.com
@@ -45,7 +45,7 @@
     build-depends:
         base >=4.7 && <5,
         containers >=0.6.7 && <0.7,
-        data-default-class >=0.1.2.0 && <0.2,
+        data-default >=0.7.1.1 && <0.8,
         lens >=5.2.3 && <5.3,
         monomer >=1.5.1.0 && <1.7,
         text >=2.0.2 && <2.1
@@ -70,7 +70,7 @@
     build-depends:
         base >=4.7 && <5,
         containers >=0.6.7 && <0.7,
-        data-default-class >=0.1.2.0 && <0.2,
+        data-default >=0.7.1.1 && <0.8,
         lens >=5.2.3 && <5.3,
         monomer >=1.5.1.0 && <1.7,
         monomer-hagrid,
@@ -102,7 +102,7 @@
     build-depends:
         base >=4.7 && <5,
         containers >=0.6.7 && <0.7,
-        data-default-class >=0.1.2.0 && <0.2,
+        data-default >=0.7.1.1 && <0.8,
         lens >=5.2.3 && <5.3,
         monomer >=1.5.1.0 && <1.7,
         monomer-hagrid,
@@ -133,7 +133,7 @@
     build-depends:
         base >=4.7 && <5,
         containers >=0.6.7 && <0.7,
-        data-default-class >=0.1.2.0 && <0.2,
+        data-default >=0.7.1.1 && <0.8,
         lens >=5.2.3 && <5.3,
         monomer >=1.5.1.0 && <1.7,
         monomer-hagrid,
@@ -173,7 +173,6 @@
         bytestring >=0.11.5.3 && <0.12,
         containers >=0.6.7 && <0.7,
         data-default >=0.7.1.1 && <0.8,
-        data-default-class >=0.1.2.0 && <0.2,
         hspec >=2 && <3,
         lens >=5.2.3 && <5.3,
         monomer >=1.5.1.0 && <1.7,
diff --git a/src/Monomer/Hagrid.hs b/src/Monomer/Hagrid.hs
--- a/src/Monomer/Hagrid.hs
+++ b/src/Monomer/Hagrid.hs
@@ -38,7 +38,7 @@
 import Control.Lens.Operators ((%~))
 import Control.Monad as X (forM_)
 import Data.Data (Typeable)
-import Data.Default.Class (Default, def)
+import Data.Default (Default, def)
 import Data.Foldable (foldl')
 import Data.Maybe (catMaybes, isNothing, maybeToList)
 import Data.Maybe as X (fromMaybe)