diff --git a/Data/AList.hs b/Data/AList.hs
--- a/Data/AList.hs
+++ b/Data/AList.hs
@@ -12,6 +12,7 @@
 
 instance Monoid (AList a) where 
  mempty = AListEmpty
+ mappend = append
 
 instance Semigroup (AList a) where
  (<>) = append
diff --git a/alist.cabal b/alist.cabal
--- a/alist.cabal
+++ b/alist.cabal
@@ -10,7 +10,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             0.1.0.3
+version:             0.1.0.4
 
 -- A short (one-line) description of the package.
 synopsis:            lists with O(1) append
@@ -67,6 +67,7 @@
   
   -- Base language which the package is written in.
   default-language:    Haskell98
+  default-extensions: Safe
 
 
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