diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,61 @@
+## [v1.5.1.2](https://github.com/diagrams/diagrams-core/tree/v1.5.1.2) (2026-04-18)
+
+- Allow `base-4.22`, `containers-0.8`, and test on GHC 9.14
+- Fix some pattern match warnings
+- Remove `semigroups` dependency
+
+## [v1.5.1.1-r4](https://github.com/diagrams/diagrams-core/tree/v1.5.1.1-r4) (2025-05-16)
+
+- Allow `monoid-extras-0.7`
+
+## [v1.5.1.1-r3](https://github.com/diagrams/diagrams-core/tree/v1.5.1.1-r3) (2025-01-30)
+
+- Allow `base-4.21` (GHC 9.12)
+
+## [v1.5.1.1-r2](https://github.com/diagrams/diagrams-core/tree/v1.5.1.1-r2) (2024-05-20)
+
+- Allow:
+  - `base-4.20` (GHC 9.10)
+  - `lens-5.3`
+  - `containers-0.7`
+- Test on GHC 9.10
+
+## [v1.5.1.1-r1](https://github.com/diagrams/diagrams-core/tree/v1.5.1.1-r1) (2024-04-20)
+
+* Allow `linear-1.23`
+
+## [v1.5.1.1](https://github.com/diagrams/diagrams-core/tree/v1.5.1.1) (2023-11-15)
+
+* Allow `base-4.19` and test on GHC 9.8
+* Fix more warnings
+
+## [v1.5.1](https://github.com/diagrams/diagrams-core/tree/v1.5.1) (2023-05-11)
+
+* Allow `base-4.18` and test on GHC 9.6 (thanks to @sergv)
+* Fix some warnings (thanks to @sergv)
+* Fix some documentation typos (thanks to @mchav)
+
+## [v1.5.0.1-r1](https://github.com/diagrams/diagrams-core/tree/v1.5.0.1-r1) (2022-11-30)
+
+* Allow `linear-1.22`
+
+## [v1.5.0.1](https://github.com/diagrams/diagrams-core/tree/v1.5.0.1) (2022-08-27)
+
+* Test with up to `base-4.17` and GHC 9.4
+* Allow `lens-5.2`
+* Fix documentation for `atLeast` and `atMost` (thanks to Igor Moreno)
+
+## [v1.5.0](https://github.com/diagrams/diagrams-core/tree/v1.5.0) (2021-05-13)
+
+* Updates for GHC 8.10 and 9.0
+* Drop support for GHC < 8.4
+* Remove deprecated `Option` type in favor of `Maybe`.  This is a
+  breaking API change.
+
+## [v1.4.2-r1](https://github.com/diagrams/diagrams-core/tree/v1.4.2-r1) (2020-02-10)
+
+* Allow `lens-4.19` and `linear-1.21`
+
 ## [v1.4.2](https://github.com/diagrams/diagrams-core/tree/v1.4.2) (2019-10-19)
 
 * New `KeyVal` constructor for `Annotation` ([PR](https://github.com/diagrams/diagrams-core/pull/104))
diff --git a/README.markdown b/README.markdown
--- a/README.markdown
+++ b/README.markdown
@@ -1,4 +1,4 @@
-[![Build Status](https://travis-ci.org/diagrams/diagrams-core.png?branch=master)](http://travis-ci.org/diagrams/diagrams-core)
+[![Build Status](https://github.com/diagrams/diagrams-core/actions/workflows/haskell-ci.yml/badge.svg)](https://github.com/diagrams/diagrams-core/actions/workflows/haskell-ci.yml)
 
 The core modules defining the basic data structures and algorithms for
 [diagrams](http://projects.haskell.org/diagrams), a Haskell embedded
diff --git a/diagrams-core.cabal b/diagrams-core.cabal
--- a/diagrams-core.cabal
+++ b/diagrams-core.cabal
@@ -1,10 +1,10 @@
 Name:                diagrams-core
-Version:             1.4.2
+Version:             1.5.1.2
 Synopsis:            Core libraries for diagrams EDSL
 Description:         The core modules underlying diagrams,
                      an embedded domain-specific language
                      for compositional, declarative drawing.
-Homepage:            http://projects.haskell.org/diagrams
+Homepage:            https://diagrams.github.io
 License:             BSD3
 License-file:        LICENSE
 Author:              Brent Yorgey
@@ -13,12 +13,12 @@
 Category:            Graphics
 Build-type:          Simple
 Cabal-version:       1.18
-Extra-source-files:  CHANGELOG.md, README.markdown, diagrams/*.svg
-extra-doc-files:     diagrams/*.svg
-Tested-with:         GHC == 7.10.2, GHC == 8.0.1, GHC == 8.2.2, GHC == 8.4.1, GHC == 8.6.1, GHC == 8.8.1
+Extra-source-files:  diagrams/*.svg
+extra-doc-files:     diagrams/*.svg, CHANGELOG.md, README.markdown
+Tested-with:         GHC ==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 || ==9.14.1
 Source-repository head
   type:     git
-  location: git://github.com/diagrams/diagrams-core.git
+  location: https://github.com/diagrams/diagrams-core.git
 
 Library
   Exposed-modules:     Diagrams.Core,
@@ -36,18 +36,17 @@
                        Diagrams.Core.Types,
                        Diagrams.Core.V
 
-  Build-depends:       base >= 4.2 && < 4.14,
-                       containers >= 0.4.2 && < 0.7,
+  Build-depends:       base >= 4.11 && < 4.23,
+                       containers >= 0.4.2 && < 0.9,
                        unordered-containers >= 0.2 && < 0.3,
-                       semigroups >= 0.8.4 && < 0.20,
-                       monoid-extras >= 0.3 && < 0.6,
+                       monoid-extras >= 0.6 && < 0.8,
                        dual-tree >= 0.2 && < 0.3,
-                       lens >= 4.0 && < 4.19,
-                       linear >= 1.11.3 && < 1.21,
+                       lens >= 4.0 && < 5.4,
+                       linear >= 1.11.3 && < 1.24,
                        adjunctions >= 4.0 && < 5.0,
                        distributive >=0.2.2 && < 1.0,
                        profunctors >= 5.0 && < 6.0,
-                       mtl
+                       mtl >= 2.2 && < 2.4
   hs-source-dirs:      src
 
   Other-extensions:    DeriveDataTypeable
diff --git a/src/Diagrams/Core.hs b/src/Diagrams/Core.hs
--- a/src/Diagrams/Core.hs
+++ b/src/Diagrams/Core.hs
@@ -26,7 +26,7 @@
 --
 -- The best place to start when learning
 -- about diagrams\' types is the user manual:
--- <http://projects.haskell.org/diagrams/doc/manual.html#type-reference>
+-- <https://diagrams.github.io/doc/manual.html#type-reference>
 -- The following list shows which types are contained in each module of
 -- "Diagrams.Core".
 --
diff --git a/src/Diagrams/Core/Compile.hs b/src/Diagrams/Core/Compile.hs
--- a/src/Diagrams/Core/Compile.hs
+++ b/src/Diagrams/Core/Compile.hs
@@ -103,8 +103,8 @@
       -- 'untangle' we have already performed the action of the
       -- transform on the style).
       (\d t -> case get d of
-                 Option Nothing   -> t
-                 Option (Just d') ->
+                 Nothing -> t
+                 Just d' ->
                    let (tr,sty) = untangle d'
                    in  Node (DStyle sty) [Node (DTransform tr) [t]]
       )
@@ -113,7 +113,7 @@
       (\a t -> Node (DAnnot a) [t])
       qd
 
--- | Convert a @DTree@ to an @RTree@ which can be used dirctly by backends.
+-- | Convert a @DTree@ to an @RTree@ which can be used directly by backends.
 --   A @DTree@ includes nodes of type @DTransform (Transformation v)@;
 --   in the @RTree@ transform is pushed down until it reaches a primitive node.
 fromDTree :: forall b v n. (Floating n, HasLinearMap v)
diff --git a/src/Diagrams/Core/Envelope.hs b/src/Diagrams/Core/Envelope.hs
--- a/src/Diagrams/Core/Envelope.hs
+++ b/src/Diagrams/Core/Envelope.hs
@@ -7,6 +7,7 @@
 {-# LANGUAGE RankNTypes                 #-}
 {-# LANGUAGE StandaloneDeriving         #-}
 {-# LANGUAGE TypeFamilies               #-}
+{-# LANGUAGE TypeOperators              #-}
 {-# LANGUAGE UndecidableInstances       #-}
 -----------------------------------------------------------------------------
 -- |
@@ -109,10 +110,10 @@
 --   The idea for envelopes came from
 --   Sebastian Setzer; see
 --   <http://byorgey.wordpress.com/2009/10/28/collecting-attributes/#comment-2030>.  See also Brent Yorgey, /Monoids: Theme and Variations/, published in the 2012 Haskell Symposium: <http://ozark.hendrix.edu/~yorgey/pub/monoid-pearl.pdf>; video: <http://www.youtube.com/watch?v=X-8NCkD2vOw>.
-newtype Envelope v n = Envelope (Option (v n -> Max n))
+newtype Envelope v n = Envelope (Maybe (v n -> Max n))
 
 instance Wrapped (Envelope v n) where
-  type Unwrapped (Envelope v n) = Option (v n -> Max n)
+  type Unwrapped (Envelope v n) = Maybe (v n -> Max n)
   _Wrapped' = iso (\(Envelope e) -> e) Envelope
 
 instance Rewrapped (Envelope v n) (Envelope v' n')
@@ -120,7 +121,7 @@
 -- | \"Apply\" an envelope by turning it into a function.  @Nothing@
 --   is returned iff the envelope is empty.
 appEnvelope :: Envelope v n -> Maybe (v n -> n)
-appEnvelope (Envelope (Option e)) = (getMax .) <$> e
+appEnvelope (Envelope e) = (getMax .) <$> e
 
 -- | A convenient way to transform an envelope, by specifying a
 --   transformation on the underlying @v n -> n@ function.  The empty
@@ -130,7 +131,7 @@
 
 -- | Create an envelope from a @v n -> n@ function.
 mkEnvelope :: (v n -> n) -> Envelope v n
-mkEnvelope = Envelope . Option . Just . (Max .)
+mkEnvelope = Envelope . Just . (Max .)
 
 -- | Create a point envelope for the given point.  A point envelope
 --   has distance zero to a bounding hyperplane in every direction.
diff --git a/src/Diagrams/Core/HasOrigin.hs b/src/Diagrams/Core/HasOrigin.hs
--- a/src/Diagrams/Core/HasOrigin.hs
+++ b/src/Diagrams/Core/HasOrigin.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE TypeFamilies          #-}
+{-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE UndecidableInstances  #-}
 
 -- The UndecidableInstances flag is needed under 6.12.3 for the
diff --git a/src/Diagrams/Core/Juxtapose.hs b/src/Diagrams/Core/Juxtapose.hs
--- a/src/Diagrams/Core/Juxtapose.hs
+++ b/src/Diagrams/Core/Juxtapose.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE TypeFamilies          #-}
+{-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE UndecidableInstances  #-}
 -----------------------------------------------------------------------------
 -- |
diff --git a/src/Diagrams/Core/Measure.hs b/src/Diagrams/Core/Measure.hs
--- a/src/Diagrams/Core/Measure.hs
+++ b/src/Diagrams/Core/Measure.hs
@@ -78,11 +78,11 @@
 scaleLocal :: Num n => n -> Measured n a -> Measured n a
 scaleLocal s = R.local (_1 *~ s)
 
--- | Calculate the smaller of two measures.
+-- | Calculate the larger of two measures.
 atLeast :: Ord n => Measure n -> Measure n -> Measure n
 atLeast = liftA2 max
 
--- | Calculate the larger of two measures.
+-- | Calculate the smaller of two measures.
 atMost :: Ord n => Measure n -> Measure n -> Measure n
 atMost = liftA2 min
 
@@ -126,7 +126,6 @@
 
 instance Monoid a => Monoid (Measured n a) where
   mempty  = pure mempty
-  mappend = liftA2 mappend
 
 instance Distributive (Measured n) where
   distribute a = Measured $ \x -> fmap (\(Measured m) -> m x) a
diff --git a/src/Diagrams/Core/Style.hs b/src/Diagrams/Core/Style.hs
--- a/src/Diagrams/Core/Style.hs
+++ b/src/Diagrams/Core/Style.hs
@@ -69,6 +69,7 @@
 import           Control.Arrow           ((***))
 import           Control.Lens            hiding (transform)
 import qualified Data.HashMap.Strict     as HM
+import           Data.Kind               (Type)
 import qualified Data.Map                as M
 import           Data.Monoid.Action      as A
 import           Data.Semigroup
@@ -111,7 +112,7 @@
 --   are simply inert/static; some are affected by transformations;
 --   and some are affected by transformations and can be modified
 --   generically.
-data Attribute (v :: * -> *) n :: * where
+data Attribute (v :: Type -> Type) n :: Type where
   Attribute  :: AttributeClass a => a -> Attribute v n
   MAttribute :: AttributeClass a => Measured n a -> Attribute v n
   TAttribute :: (AttributeClass a, Transformable a, V a ~ v, N a ~ n) => a -> Attribute v n
diff --git a/src/Diagrams/Core/Trace.hs b/src/Diagrams/Core/Trace.hs
--- a/src/Diagrams/Core/Trace.hs
+++ b/src/Diagrams/Core/Trace.hs
@@ -1,11 +1,12 @@
-{-# LANGUAGE ConstraintKinds            #-}
 {-# LANGUAGE CPP                        #-}
+{-# LANGUAGE ConstraintKinds            #-}
 {-# LANGUAGE FlexibleContexts           #-}
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses      #-}
 {-# LANGUAGE StandaloneDeriving         #-}
 {-# LANGUAGE TypeFamilies               #-}
+{-# LANGUAGE TypeOperators              #-}
 {-# LANGUAGE UndecidableInstances       #-}
 
 {-# OPTIONS_GHC -fno-warn-unused-imports #-}
diff --git a/src/Diagrams/Core/Transform.hs b/src/Diagrams/Core/Transform.hs
--- a/src/Diagrams/Core/Transform.hs
+++ b/src/Diagrams/Core/Transform.hs
@@ -6,10 +6,9 @@
 {-# LANGUAGE ScopedTypeVariables        #-}
 {-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE TypeOperators              #-}
-{-# LANGUAGE TypeSynonymInstances       #-}
 {-# LANGUAGE UndecidableInstances       #-}
-{-# OPTIONS_GHC -fno-warn-unused-imports       #-}
------------------------------------------------------------------------------
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+
 -- |
 -- Module      :  Diagrams.Core.Transform
 -- Copyright   :  (c) 2011-2015 diagrams-core team (see LICENSE)
@@ -232,22 +231,23 @@
 
 -- Remove the nth element from a list
 remove :: Int -> [a] -> [a]
-remove n xs = ys ++ tail zs
-  where
-    (ys, zs) = splitAt n xs
+remove n xs | n < 0 = xs
+remove n xs = ys ++ drop 1 zs
+ where
+  (ys, zs) = splitAt n xs
 
--- Minor matrix of cofactore C(i,j)
+-- Minor matrix of cofactor C(i,j)
 minor :: Int -> Int -> [[a]] -> [[a]]
 minor i j xs = remove j $ map (remove i) xs
 
--- The determinant of a square matrix represented as a list of lists
+-- The determinant of a square matrix represented as a nonempty list of lists
 -- representing column vectors, that is [column].
 det :: Num a => [[a]] -> a
-det (a:[]) = head a
-det m = sum [(-1)^i * (c1 !! i) * det (minor i 0 m) | i <- [0 .. (n-1)]]
-  where
-    c1 = head m
-    n = length m
+det [] = error "determinant of empty matrix!"
+det [a : _] = a
+det m@(c1 : _) = sum [(-1) ^ i * (c1 !! i) * det (minor i 0 m) | i <- [0 .. (n - 1)]]
+ where
+  n = length m
 
 -- | Convert a vector v to a list of scalars.
 listRep :: Foldable v => v n -> [n]
diff --git a/src/Diagrams/Core/Types.hs b/src/Diagrams/Core/Types.hs
--- a/src/Diagrams/Core/Types.hs
+++ b/src/Diagrams/Core/Types.hs
@@ -136,6 +136,7 @@
                                             prism', view, (^.), _Wrapped,
                                             _Wrapping)
 import           Control.Monad             (mplus)
+import           Data.Kind                 (Type)
 import           Data.List                 (isSuffixOf)
 import qualified Data.Map                  as M
 import           Data.Maybe                (fromMaybe, listToMaybe)
@@ -224,7 +225,7 @@
 -- | Extract the (total) transformation from a downwards annotation
 --   value.
 transfFromAnnot :: (Additive v, Num n) => DownAnnots v n -> Transformation v n
-transfFromAnnot = option mempty killR . fst
+transfFromAnnot = maybe mempty killR . fst
 
 -- | A leaf in a 'QDiagram' tree is either a 'Prim', or a \"delayed\"
 --   @QDiagram@ which expands to a real @QDiagram@ once it learns the
@@ -347,7 +348,7 @@
 -- | A useful variant of 'getU' which projects out a certain
 --   component.
 getU' :: (Monoid u', u :>: u') => D.DUALTree d u a l -> u'
-getU' = maybe mempty (option mempty id . get) . D.getU
+getU' = maybe mempty (maybe mempty id . get) . D.getU
 
 -- | Lens onto the 'Envelope' of a 'QDiagram'.
 envelope :: (OrderedField n, Metric v, Monoid' m)
@@ -841,13 +842,13 @@
   --   able to convert primitives into this type; how these rendered
   --   primitives are combined into an ultimate 'Result' is completely
   --   up to the backend.
-  data Render b v n :: *
+  data Render b v n :: Type
 
   -- | The result of running/interpreting a rendering operation.
-  type Result b v n :: *
+  type Result b v n :: Type
 
   -- | Backend-specific rendering options.
-  data Options b v n :: *
+  data Options b v n :: Type
 
   -- | 'adjustDia' allows the backend to make adjustments to the final
   --   diagram (e.g. to adjust the size based on the options) before
diff --git a/src/Diagrams/Core/V.hs b/src/Diagrams/Core/V.hs
--- a/src/Diagrams/Core/V.hs
+++ b/src/Diagrams/Core/V.hs
@@ -20,6 +20,7 @@
   , InSpace, SameSpace
   ) where
 
+import           Data.Kind (Type)
 import           Data.Map
 import           Data.Monoid.Coproduct
 import           Data.Monoid.Deletable
@@ -38,7 +39,7 @@
 --   the associated vector space. The resulting vector space has kind @* -> *@
 --   which means it takes another value (a number) and returns a concrete
 --   vector. For example 'V2' has kind @* -> *@ and @V2 Double@ is a vector.
-type family V a :: * -> *
+type family V a :: Type -> Type
 
 -- Note, to use these instances one often needs a constraint of the form
 --   V a ~ V b, etc.
@@ -47,7 +48,7 @@
 
 type instance V (a -> b)   = V b
 type instance V [a]        = V a
-type instance V (Option a) = V a
+type instance V (Maybe a) = V a
 type instance V (Set a)    = V a
 type instance V (Map k a)  = V a
 
@@ -56,14 +57,14 @@
 type instance V (m :+: n)     = V m
 
 -- | The numerical field for the object, the number type used for calculations.
-type family N a :: *
+type family N a :: Type
 
 type instance N (a,b)   = N a
 type instance N (a,b,c) = N a
 
 type instance N (a -> b)   = N b
 type instance N [a]        = N a
-type instance N (Option a) = N a
+type instance N (Maybe a) = N a
 type instance N (Set a)    = N a
 type instance N (Map k a)  = N a
 
@@ -71,7 +72,7 @@
 type instance N (Split m)     = N m
 type instance N (m :+: n)     = N m
 
--- | Conveient type alias to retrieve the vector type associated with an
+-- | Convenient type alias to retrieve the vector type associated with an
 --   object's vector space. This is usually used as @Vn a ~ v n@ where @v@ is
 --   the vector space and @n@ is the numerical field.
 type Vn a = V a (N a)