diff --git a/README.md b/README.md
index b70fb36a..f507b5f4 100644
--- a/README.md
+++ b/README.md
@@ -430,6 +430,13 @@ instance semigroupStrMap :: (P.Semigroup a) => P.Semigroup (StrMap a)
 ```
 
 
+#### `monoidStrMap`
+
+``` purescript
+instance monoidStrMap :: (P.Semigroup a) => Monoid (StrMap a)
+```
+
+
 
 ## Module Data.StrMap.ST
 
diff --git a/src/Data/StrMap.purs b/src/Data/StrMap.purs
index df5ab307..0920d7ce 100644
--- a/src/Data/StrMap.purs
+++ b/src/Data/StrMap.purs
@@ -293,3 +293,6 @@ map = P.(<$>)
 
 instance semigroupStrMap :: (P.Semigroup a) => P.Semigroup (StrMap a) where
   (<>) m1 m2 = mutate (\s -> foldM (\s k v2 -> SM.poke s k (runFn4 _lookup v2 (\v1 -> v1 P.<> v2) k m2)) s m1) m2
+
+instance monoidStrMap :: (P.Semigroup a) => Monoid (StrMap a) where
+  mempty = empty