diff --git a/Data/Matrix.hs b/Data/Matrix.hs
--- a/Data/Matrix.hs
+++ b/Data/Matrix.hs
@@ -173,12 +173,12 @@
 ---- MONOID INSTANCE
 
 instance Monoid a => S.Semigroup (Matrix a) where
-  (<>) = mappend
+  m <> m' = matrix (max (nrows m) (nrows m')) (max (ncols m) (ncols m')) $ uncurry zipTogether
+    where zipTogether row column = fromMaybe mempty $ safeGet row column m <> safeGet row column m'
 
 instance Monoid a => Monoid (Matrix a) where
   mempty = fromList 1 1 [mempty]
-  mappend m m' = matrix (max (nrows m) (nrows m')) (max (ncols m) (ncols m')) $ uncurry zipTogether
-    where zipTogether row column = fromMaybe mempty $ safeGet row column m <> safeGet row column m'
+  mappend = (<>)
 
 
 -------------------------------------------------------
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,7 @@
+## 0.3.6.4
+* Metadata update.
+* Make Semigroip/Monoid definitions canonical (Ryan Hendrickson).
+
 ## 0.3.6.3
 * Metadata update.
 
diff --git a/license b/license
--- a/license
+++ b/license
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2023 Daniel Casanueva
+Copyright (c) 2025 Daniel Casanueva
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/matrix.cabal b/matrix.cabal
--- a/matrix.cabal
+++ b/matrix.cabal
@@ -1,13 +1,13 @@
 cabal-version: 3.0
 name: matrix
-version: 0.3.6.3
+version: 0.3.6.4
 author: Daniel Casanueva
 category: Math
 build-type: Simple
 license: MIT
 license-file: license
-maintainer: Daniel Casanueva (daniel.casanueva `at` proton.me)
-bug-reports: https://gitlab.com/daniel-casanueva/haskell/matrix/-/issues
+maintainer: Daniel Casanueva (coding `at` danielcasanueva.eu)
+bug-reports: https://codeberg.org/daniel-casanueva/matrix/issues
 synopsis: A native implementation of matrix operations.
 description:
   Matrix library. Basic operations and some algorithms.