diff --git a/CHANGES.markdown b/CHANGES.markdown
--- a/CHANGES.markdown
+++ b/CHANGES.markdown
@@ -1,8 +1,17 @@
+0.3.0.4 (19 Dec 2024)
+---------------------
+
+- Allow `base-4.21` and test on GHC 9.12
+- Fix warnings
+
 0.3.0.3 (10 July 2023)
 ---------------------
 
 - Allow `base-4.18` (GHC 9.6)
 - Fix cabal warning
+
+- r1 (31 Jan 2024): allow `base-4.19` (GHC 9.8)
+- r2 (18 Sep 2024): allow `base-4.20`, `containers-0.7`, and test on GHC 9.10
 
 0.3.0.2 (22 Feb 2019)
 ---------------------
diff --git a/palette.cabal b/palette.cabal
--- a/palette.cabal
+++ b/palette.cabal
@@ -1,5 +1,5 @@
 Name:                palette
-Version:             0.3.0.3
+Version:             0.3.0.4
 Synopsis:            Utilities for choosing and creating color schemes.
 Description:         Sets of predefined colors and tools for choosing and
                      creating color schemes. Random colors.
@@ -15,7 +15,7 @@
 Cabal-version:       1.18
 Extra-source-files:  README.markdown, diagrams/*.svg
 Extra-doc-files:     diagrams/*.svg, CHANGES.markdown
-Tested-with:         GHC ==8.0.2 || == 8.2.2 || == 8.4.4 || ==8.6.5 || ==8.8.4 || ==8.10.7 || ==9.0.2 || ==9.2.7 || ==9.4.5 || ==9.6.1
+Tested-with:         GHC ==8.0.2 || == 8.2.2 || == 8.4.4 || ==8.6.5 || ==8.8.4 || ==8.10.7 || ==9.0.2 || ==9.2.8 || ==9.4.8 || ==9.6.6 || ==9.8.2 || ==9.10.1 || ==9.12.1
 Source-repository head
   type:     git
   location: http://github.com/diagrams/palette.git
@@ -28,9 +28,9 @@
                        Data.Colour.Palette.Types
                        Data.Colour.Palette.RandomColor
 
-  Build-depends:       base >= 4.2 && < 4.19,
+  Build-depends:       base >= 4.2 && < 4.22,
                        array >= 0.4 && < 0.6,
                        colour >= 2.3 && < 3.0,
-                       containers >= 0.5 && < 0.7,
+                       containers >= 0.5 && < 0.8,
                        MonadRandom >= 0.5 && < 0.7
   hs-source-dirs:      src
diff --git a/src/Data/Colour/Palette/RandomColor.hs b/src/Data/Colour/Palette/RandomColor.hs
--- a/src/Data/Colour/Palette/RandomColor.hs
+++ b/src/Data/Colour/Palette/RandomColor.hs
@@ -41,6 +41,7 @@
 import           Data.Colour.RGBSpace.HSV
 import           Data.Colour.SRGB            (RGB (..), sRGB)
 import           Data.List                   (find)
+import qualified Data.List.NonEmpty as NE
 import           Data.Maybe                  (fromMaybe)
 
 getColorDefinition :: Hue -> ColorDefinition
@@ -106,9 +107,9 @@
 saturationRange hue = result
   where
     lbs = lowerBounds $ getColorDefinition hue
-    result = case lbs of
-      [] -> error "Can\'t obtain saturationRange from an empty lowerBounds"
-      _  -> (fst . head $ lbs, fst . last $ lbs)
+    result = case NE.nonEmpty lbs of
+      Nothing -> error "Can\'t obtain saturationRange from an empty lowerBounds"
+      Just lbsNE -> (fst . NE.head $ lbsNE, fst . NE.last $ lbsNE)
 
 randomSaturation :: MonadRandom m => Hue -> Luminosity -> m Int
 randomSaturation HueMonochrome _   = return 0