diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,9 @@
+* 0.6.1: 16 Nov 2021
+
+- Add more efficient `stimes` implementations for several `Semigroup`
+  instances.  Thanks to BlackCapCoder for the patch!
+- Allow `base-4.16` and test on GHC 9.2.1.
+
 * 0.6: 8 May 2021
 
 - Updates for GHC 8.10 and 9.0.
diff --git a/monoid-extras.cabal b/monoid-extras.cabal
--- a/monoid-extras.cabal
+++ b/monoid-extras.cabal
@@ -1,5 +1,5 @@
 name:                monoid-extras
-version:             0.6
+version:             0.6.1
 synopsis:            Various extra monoid-related definitions and utilities
 description:         Various extra monoid-related definitions and utilities,
                      such as monoid actions, monoid coproducts, semi-direct
@@ -14,7 +14,7 @@
 category:            Data
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC == 8.4.4, GHC == 8.6.5, GHC == 8.8.4, GHC == 8.10.4, GHC == 9.0.1
+tested-with:         GHC ==8.4.4 || ==8.6.5 || ==8.8.4 || ==8.10.4 || ==9.0.1 || ==9.2.1
 
 source-repository head
   type: git
@@ -36,7 +36,7 @@
                      Data.Monoid.Split,
                      Data.Monoid.WithSemigroup
 
-  build-depends:     base >= 4.11 && < 4.16,
+  build-depends:     base >= 4.11 && < 4.17,
                      groups < 0.6,
                      semigroupoids >= 4.0 && < 5.4
 
diff --git a/src/Data/Monoid/Cut.hs b/src/Data/Monoid/Cut.hs
--- a/src/Data/Monoid/Cut.hs
+++ b/src/Data/Monoid/Cut.hs
@@ -61,6 +61,9 @@
   (m1  :||: m2) <> (Uncut m2')   = m1        :||: m2 <> m2'
   (m11 :||: _)  <> (_ :||: m22)  = m11       :||: m22
 
+  stimes n (Uncut m) = Uncut (stimes n m)
+  stimes _ (m      ) = m
+
 instance (Semigroup m, Monoid m) => Monoid (Cut m) where
   mempty  = Uncut mempty
   mappend = (<>)
diff --git a/src/Data/Monoid/Deletable.hs b/src/Data/Monoid/Deletable.hs
--- a/src/Data/Monoid/Deletable.hs
+++ b/src/Data/Monoid/Deletable.hs
@@ -77,6 +77,13 @@
     | l1 <  r2  = Deletable (r1 + r2 - l1) m2 l2
     | otherwise = Deletable r1 m1 (l2 + l1 - r2)
 
+  stimes n (Deletable r m l)
+    | r == l    = Deletable r (stimes n m) l
+    | l <  r    = Deletable (i*(r-l) + l) m l
+    | otherwise = Deletable r m (i*(l-r) + r)
+    where
+      i = fromIntegral n :: Int
+
 instance (Semigroup m, Monoid m) => Monoid (Deletable m) where
   mempty = Deletable 0 mempty 0
   mappend = (<>)
diff --git a/src/Data/Monoid/Recommend.hs b/src/Data/Monoid/Recommend.hs
--- a/src/Data/Monoid/Recommend.hs
+++ b/src/Data/Monoid/Recommend.hs
@@ -58,6 +58,9 @@
   Commit a    <> Recommend _ = Commit a
   Commit a    <> Commit b    = Commit (a <> b)
 
+  stimes n (Recommend m) = Recommend (stimes n m)
+  stimes n (Commit    m) = Commit    (stimes n m)
+
 instance (Semigroup a, Monoid a) => Monoid (Recommend a) where
   mappend = (<>)
   mempty  = Recommend mempty
diff --git a/src/Data/Monoid/Split.hs b/src/Data/Monoid/Split.hs
--- a/src/Data/Monoid/Split.hs
+++ b/src/Data/Monoid/Split.hs
@@ -67,6 +67,10 @@
   (m1  :| m2)  <> (M m2')      = m1                :| m2 <> m2'
   (m11 :| m12) <> (m21 :| m22) = m11 <> m12 <> m21 :| m22
 
+  stimes n (M m     ) = M (stimes n m)
+  stimes 1 (m       ) = m
+  stimes n (m1 :| m2) = m1 <> stimes (pred n) (m2 <> m1) :| m2
+
 instance (Semigroup m, Monoid m) => Monoid (Split m) where
   mempty  = M mempty
   mappend = (<>)