diff --git a/changelog b/changelog
--- a/changelog
+++ b/changelog
@@ -1,3 +1,7 @@
+0.0.3
+
+* Monoid instances on `NotZeroOr` and `AccNotZeroOr`.
+
 0.0.2
 
 * Semigroup instances on `NotZeroOr` and `AccNotZeroOr`.
diff --git a/notzero.cabal b/notzero.cabal
--- a/notzero.cabal
+++ b/notzero.cabal
@@ -1,5 +1,5 @@
 name:               notzero
-version:            0.0.2
+version:            0.0.3
 license:            BSD3
 license-file:       LICENSE
 author:             Tony Morris <ʇǝu˙sıɹɹoɯʇ@ןןǝʞsɐɥ> <dibblego>
diff --git a/src/Data/AccNotZeroOr.hs b/src/Data/AccNotZeroOr.hs
--- a/src/Data/AccNotZeroOr.hs
+++ b/src/Data/AccNotZeroOr.hs
@@ -16,6 +16,7 @@
 import Data.Eq(Eq)
 import Data.Functor.Alt
 import Data.Functor.Identity(Identity(Identity))
+import Data.Monoid(Monoid(mappend, mempty))
 import Data.NotZero(NotZero)
 import Data.NotZeroOr(NotZeroOr(IsNotZero, OrNotZero), NotZeroOrT, isoNumber, isoNotZeroOrT)
 import Data.Semigroup(Semigroup((<>)))
@@ -96,6 +97,12 @@
     OrAccNotZero x
   IsAccNotZero _ <> y =
     y
+    
+instance Monoid x => Monoid (AccNotZeroOr f a x) where
+  mappend =
+    (<>)
+  mempty =
+    OrAccNotZero mempty
 
 instance Functor f => Functor (AccNotZeroOr f a) where
   fmap _ (IsAccNotZero z) =
diff --git a/src/Data/NotZeroOr.hs b/src/Data/NotZeroOr.hs
--- a/src/Data/NotZeroOr.hs
+++ b/src/Data/NotZeroOr.hs
@@ -23,6 +23,7 @@
 import Data.Functor.Bind.Trans(BindTrans(liftB))
 import Data.Functor.Identity(Identity(Identity))
 import Data.Maybe(Maybe(Nothing, Just))
+import Data.Monoid(Monoid(mappend, mempty))
 import Data.NotZero(NotZero, notZero, getNotZero)
 import Data.Ord(Ord)
 import Data.Semigroup(Semigroup((<>)))
@@ -98,6 +99,12 @@
   IsNotZero _ <> y =
     y
     
+instance Monoid x => Monoid (NotZeroOr a x) where
+  mappend =
+    (<>)
+  mempty =
+    OrNotZero mempty
+
 instance Functor (NotZeroOr a) where
   fmap _ (IsNotZero z) =
     IsNotZero z