diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,11 @@
+0.8.7 [2023.02.18]
+------------------
+* Define `Foldable1` and `Bifoldable1` instances for `Tagged`. These instances
+  were originally defined in the `semigroupoids` library, and they have now
+  been migrated to `tagged` as a side effect of adapting to
+  [this Core Libraries Proposal](https://github.com/haskell/core-libraries-committee/issues/9),
+  which adds `Foldable1` and `Bifoldable1` to `base`.
+
 0.8.6.1 [2020.12.28]
 --------------------
 * Mark all modules as explicitly Safe or Trustworthy.
diff --git a/src/Data/Tagged.hs b/src/Data/Tagged.hs
--- a/src/Data/Tagged.hs
+++ b/src/Data/Tagged.hs
@@ -46,9 +46,9 @@
     , reproxy
     ) where
 
-#if MIN_VERSION_base(4,8,0)
+#if MIN_VERSION_base(4,8,0) && !(MIN_VERSION_base(4,18,0))
 import Control.Applicative (liftA2)
-#else
+#elif !(MIN_VERSION_base(4,8,0))
 import Control.Applicative ((<$>), liftA2, Applicative(..))
 import Data.Traversable (Traversable(..))
 import Data.Monoid
@@ -73,6 +73,10 @@
 import Data.Bifoldable (Bifoldable(..))
 import Data.Bitraversable (Bitraversable(..))
 #endif
+#if MIN_VERSION_base(4,18,0)
+import Data.Foldable1 (Foldable1(..))
+import Data.Bifoldable1 (Bifoldable1(..))
+#endif
 #ifdef __GLASGOW_HASKELL__
 import Data.Data
 #endif
@@ -194,6 +198,16 @@
 instance Bitraversable Tagged where
     bitraverse _ g (Tagged b) = Tagged <$> g b
     {-# INLINE bitraverse #-}
+#endif
+
+#if MIN_VERSION_base(4,18,0)
+instance Foldable1 (Tagged a) where
+  foldMap1 f (Tagged a) = f a
+  {-# INLINE foldMap1 #-}
+
+instance Bifoldable1 Tagged where
+  bifoldMap1 _ g (Tagged b) = g b
+  {-# INLINE bifoldMap1 #-}
 #endif
 
 #ifdef MIN_VERSION_deepseq
diff --git a/tagged.cabal b/tagged.cabal
--- a/tagged.cabal
+++ b/tagged.cabal
@@ -1,5 +1,5 @@
 name:           tagged
-version:        0.8.6.1
+version:        0.8.7
 license:        BSD3
 license-file:   LICENSE
 author:         Edward A. Kmett
@@ -24,8 +24,12 @@
              , GHC == 8.2.2
              , GHC == 8.4.4
              , GHC == 8.6.5
-             , GHC == 8.8.3
-             , GHC == 8.10.1
+             , GHC == 8.8.4
+             , GHC == 8.10.7
+             , GHC == 9.0.2
+             , GHC == 9.2.5
+             , GHC == 9.4.4
+             , GHC == 9.6.1
 
 source-repository head
   type: git
@@ -74,13 +78,13 @@
 
   if impl(ghc>=7.6)
     exposed-modules: Data.Proxy.TH
-    build-depends: template-haskell >= 2.8 && < 2.18
+    build-depends: template-haskell >= 2.8 && < 2.21
 
   if flag(deepseq)
     build-depends: deepseq >= 1.1 && < 1.5
 
   if flag(transformers)
-    build-depends: transformers        >= 0.2 && < 0.6
+    build-depends: transformers        >= 0.2 && < 0.7
 
     -- Ensure Data.Functor.Classes is always available
     if impl(ghc >= 7.10) || impl(ghcjs)