diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+# 2.1.1
+* Restore support for `semigroups-0.16.1`
+
 # 2.1
 * Require `semigroups` >= 0.17
 * Added `showsToShowb` and `showbToShows` to `TextShow`
diff --git a/src/TextShow/Data/Fixed.hs b/src/TextShow/Data/Fixed.hs
--- a/src/TextShow/Data/Fixed.hs
+++ b/src/TextShow/Data/Fixed.hs
@@ -26,11 +26,10 @@
 import Data.Fixed (Fixed(..))
 import Data.Int (Int64)
 import Data.Monoid.Compat ((<>))
-import Data.Semigroup (mtimesDefault)
 import Data.Text.Lazy.Builder (singleton)
 
 import TextShow.Data.Integral ()
-import TextShow.Utils (lengthB)
+import TextShow.Utils (lengthB, mtimesDefault)
 #else
 import Data.Fixed (Fixed, showFixed)
 import Data.Text.Lazy.Builder (fromString)
diff --git a/src/TextShow/Foreign/Ptr.hs b/src/TextShow/Foreign/Ptr.hs
--- a/src/TextShow/Foreign/Ptr.hs
+++ b/src/TextShow/Foreign/Ptr.hs
@@ -23,7 +23,6 @@
     ) where
 
 import Data.Monoid.Compat ((<>))
-import Data.Semigroup (mtimesDefault)
 import Data.Text.Lazy.Builder (Builder, singleton)
 
 import Foreign.ForeignPtr (ForeignPtr)
@@ -36,7 +35,7 @@
 
 import TextShow.Classes (TextShow(showb, showbPrec), TextShow1(..))
 import TextShow.Data.Integral (showbHex, showbIntPrec, showbWord)
-import TextShow.Utils (lengthB)
+import TextShow.Utils (lengthB, mtimesDefault)
 
 #include "MachDeps.h"
 #include "inline.h"
diff --git a/src/TextShow/GHC/Fingerprint.hs b/src/TextShow/GHC/Fingerprint.hs
--- a/src/TextShow/GHC/Fingerprint.hs
+++ b/src/TextShow/GHC/Fingerprint.hs
@@ -24,7 +24,6 @@
     ) where
 
 import Data.Monoid.Compat ((<>))
-import Data.Semigroup (mtimesDefault)
 import Data.Text.Lazy.Builder (Builder, singleton)
 import Data.Word (Word64)
 
@@ -32,7 +31,7 @@
 
 import TextShow.Classes (TextShow(showb))
 import TextShow.Data.Integral (showbHex)
-import TextShow.Utils (lengthB)
+import TextShow.Utils (lengthB, mtimesDefault)
 
 -- | Convert a 'Fingerprint' to a 'Builder'.
 -- This function is only available with @base-4.4.0.0@ or later.
diff --git a/src/TextShow/Utils.hs b/src/TextShow/Utils.hs
--- a/src/TextShow/Utils.hs
+++ b/src/TextShow/Utils.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP       #-}
 {-# LANGUAGE MagicHash #-}
 
 {-|
@@ -10,11 +11,26 @@
 
 Miscellaneous utility functions.
 -}
-module TextShow.Utils where
+module TextShow.Utils (
+      i2d
+    , isInfixTypeCon
+    , isTupleString
+    , lengthB
+    , mtimesDefault
+    , toString
+    , toText
+    , unlinesB
+    , unwordsB
+    ) where
 
 import Data.Int (Int64)
 import Data.Text (Text)
 import Data.Monoid.Compat ((<>))
+#if MIN_VERSION_semigroups(0,17,0)
+import Data.Semigroup (mtimesDefault)
+#else
+import Data.Semigroup (timesN)
+#endif
 import Data.Text.Lazy (length, toStrict, unpack)
 import Data.Text.Lazy.Builder (Builder, singleton, toLazyText)
 
@@ -48,6 +64,15 @@
 lengthB :: Builder -> Int64
 lengthB = length . toLazyText
 {-# INLINE lengthB #-}
+
+#if !(MIN_VERSION_semigroups(0,17,0))
+-- | Repeat a value @n@ times.
+--
+-- > mtimesDefault n a = a <> a <> ... <> a  -- using <> (n-1) times
+mtimesDefault :: (Integral b, Monoid a) => b -> a -> a
+mtimesDefault = timesN . fromIntegral
+{-# INLINE mtimesDefault #-}
+#endif
 
 -- | Convert a 'Builder' to a 'String' (without surrounding it with double quotes,
 -- as 'show' would).
diff --git a/text-show.cabal b/text-show.cabal
--- a/text-show.cabal
+++ b/text-show.cabal
@@ -1,5 +1,5 @@
 name:                text-show
-version:             2.1
+version:             2.1.1
 synopsis:            Efficient conversion of values into Text
 description:         @text-show@ offers a replacement for the @Show@ typeclass intended
                      for use with @Text@ instead of @String@s. This package was created
@@ -142,7 +142,7 @@
                      , ghc-prim
                      , integer-gmp
                      , nats               >= 0.1     && < 2
-                     , semigroups         >= 0.17    && < 1
+                     , semigroups         >= 0.16.1  && < 1
                      , tagged             >= 0.4.4   && < 1
                      , text               >= 0.11.1  && < 1.3
                      , template-haskell   >= 2.5     && < 2.12
@@ -157,7 +157,7 @@
   install-includes:    inline.h
                      , utils.h
 
-test-suite text-show-spec
+test-suite spec
   type:                exitcode-stdio-1.0
   main-is:             Spec.hs
   other-modules:       Derived.DataFamilies
@@ -314,7 +314,7 @@
                      , quickcheck-instances >= 0.1    && < 0.4
                      , tagged               >= 0.8.1  && < 1
                      , text                 >= 0.11.1 && < 1.3
-                     , text-show            == 2.1
+                     , text-show            == 2.1.1
                      , transformers         >= 0.2.1  && < 0.5
                      , transformers-compat  >= 0.3    && < 1
                      , void                 >= 0.5    && < 1