--- a/Graphics/PS/PS.hs
+++ b/Graphics/PS/PS.hs
@@ -14,2 +14,3 @@ import qualified Graphics.PS.Paper as P
 import qualified Graphics.PS.Image as I
+import qualified Data.Semigroup as S
 
@@ -248,2 +249,6 @@ newtype MonadMonoid m = MonadMonoid {appMonadMonoid :: m ()}
 
+instance Monad m => S.Semigroup (MonadMonoid m) where
+   (<>) (MonadMonoid a) (MonadMonoid b) =
+      MonadMonoid (a >> b)
+
 instance Monad m => Monoid (MonadMonoid m) where
--- a/Graphics/PS/Statistics.hs
+++ b/Graphics/PS/Statistics.hs
@@ -6,2 +6,3 @@ import Graphics.PS.Image
 import Graphics.PS.Path
+import qualified Data.Semigroup as S
 
@@ -16,2 +17,8 @@ data Statistics = Statistics {nMoveTo :: Integer
 
+instance S.Semigroup Statistics where
+    (<>) p q =
+        let (Statistics m1 l1 c1 f1 g1 t1) = p
+            (Statistics m2 l2 c2 f2 g2 t2) = q
+        in Statistics (m1+m2) (l1+l2) (c1+c2) (f1+f2) (g1+g2) (t1+t2)
+
 instance Monoid Statistics where