diff --git a/Text/Pandoc/Builder.hs b/Text/Pandoc/Builder.hs
--- a/Text/Pandoc/Builder.hs
+++ b/Text/Pandoc/Builder.hs
@@ -176,11 +176,7 @@
 import Data.Data
 import Control.Arrow ((***))
 import GHC.Generics (Generic)
-#if MIN_VERSION_base(4,9,0)
 import Data.Semigroup
-#else
-import Data.Monoid
-#endif
 
 #if MIN_VERSION_base(4,5,0)
 -- (<>) is defined in Data.Monoid
diff --git a/Text/Pandoc/Walk.hs b/Text/Pandoc/Walk.hs
--- a/Text/Pandoc/Walk.hs
+++ b/Text/Pandoc/Walk.hs
@@ -93,14 +93,14 @@
 
 module Text.Pandoc.Walk (Walkable(..))
 where
-import Control.Applicative (Applicative (pure), (<$>), (<*>))
+import Control.Applicative ()
 import Control.Monad ((>=>))
 import Data.Functor.Identity (Identity (runIdentity))
 import Text.Pandoc.Definition
 import qualified Data.Traversable as T
-import Data.Traversable (Traversable)
+import Data.Traversable ()
 import qualified Data.Foldable as F
-import Data.Foldable (Foldable)
+import Data.Foldable ()
 #if MIN_VERSION_base(4,8,0)
 import Data.Monoid ((<>))
 #else
diff --git a/changelog b/changelog
--- a/changelog
+++ b/changelog
@@ -1,3 +1,12 @@
+[1.17.4.2]
+
+  * Fix compiler warnings.
+
+[1.17.4.1]
+
+  * Import Semigroups when needed rather than using CPP.
+  * Bump criterion upper bound.
+
 [1.17.4]
 
   * Add Semigroup instances for Pandoc, Meta, Inlines, Blocks
diff --git a/pandoc-types.cabal b/pandoc-types.cabal
--- a/pandoc-types.cabal
+++ b/pandoc-types.cabal
@@ -1,5 +1,5 @@
 Name:                pandoc-types
-Version:             1.17.4.1
+Version:             1.17.4.2
 Synopsis:            Types for representing a structured document
 Description:         @Text.Pandoc.Definition@ defines the 'Pandoc' data
                      structure, which is used by pandoc to represent