diff --git a/base-compat-batteries/CHANGES.markdown b/base-compat-batteries/CHANGES.markdown
index df5620c..84500cb 100644
--- a/base-compat-batteries/CHANGES.markdown
+++ b/base-compat-batteries/CHANGES.markdown
@@ -5,6 +5,10 @@
  - Require `OneTuple-0.4` or later on GHC 7.4+, as that is the first `OneTuple`
    release to backport the `MkSolo` data constuctor for `Solo`. See
    `Data.Tuple.Compat`.
+ - Introduce `Data.Foldable1.Compat` and `Data.Bifoldable1.Compat` modules,
+   which correspond to changes made in `base-4.18.0.0`. `base-compat-batteries`
+   uses the `foldable1-classes-compat` library to backport this code to older
+   versions of `base`.
  - Depend on `bifunctor-classes-compat` to backport the `Bifunctor`,
    `Bifoldable`, and `Bitraversable` classes instead of the
    `bifunctors` library, which has more dependencies.
diff --git a/base-compat-batteries/base-compat-batteries.cabal b/base-compat-batteries/base-compat-batteries.cabal
index cc0cb4a..72ba89c 100644
--- a/base-compat-batteries/base-compat-batteries.cabal
+++ b/base-compat-batteries/base-compat-batteries.cabal
@@ -72,7 +72,8 @@ library
       contravariant >= 1.5 && < 1.6
   if !impl(ghc >= 9.6)
     build-depends:
-      OneTuple >= 0.4 && < 0.5
+      foldable1-classes-compat >= 0.1 && < 0.2,
+      OneTuple                 >= 0.4 && < 0.5
   ghc-options:
       -fno-warn-duplicate-exports
   if impl(ghc >= 7.10)
@@ -91,6 +92,7 @@ library
       Control.Monad.ST.Lazy.Unsafe.Compat
       Control.Monad.ST.Unsafe.Compat
       Data.Bifoldable.Compat
+      Data.Bifoldable1.Compat
       Data.Bifunctor.Compat
       Data.Bitraversable.Compat
       Data.Bits.Compat
@@ -98,6 +100,7 @@ library
       Data.Complex.Compat
       Data.Either.Compat
       Data.Foldable.Compat
+      Data.Foldable1.Compat
       Data.Function.Compat
       Data.Functor.Compat
       Data.Functor.Compose.Compat
@@ -155,6 +158,7 @@ library
       Control.Monad.ST.Lazy.Unsafe.Compat.Repl.Batteries
       Control.Monad.ST.Unsafe.Compat.Repl.Batteries
       Data.Bifoldable.Compat.Repl.Batteries
+      Data.Bifoldable1.Compat.Repl.Batteries
       Data.Bifunctor.Compat.Repl.Batteries
       Data.Bitraversable.Compat.Repl.Batteries
       Data.Bits.Compat.Repl.Batteries
@@ -162,6 +166,7 @@ library
       Data.Complex.Compat.Repl.Batteries
       Data.Either.Compat.Repl.Batteries
       Data.Foldable.Compat.Repl.Batteries
+      Data.Foldable1.Compat.Repl.Batteries
       Data.Function.Compat.Repl.Batteries
       Data.Functor.Compat.Repl.Batteries
       Data.Functor.Compose.Compat.Repl.Batteries
diff --git a/base-compat-batteries/src/Data/Bifoldable1/Compat.hs b/base-compat-batteries/src/Data/Bifoldable1/Compat.hs
new file mode 100644
index 0000000..b423d80
--- /dev/null
+++ b/base-compat-batteries/src/Data/Bifoldable1/Compat.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE CPP, NoImplicitPrelude, PackageImports #-}
+module Data.Bifoldable1.Compat (
+  module Base
+) where
+
+#if MIN_VERSION_base(4,18,0)
+import "base-compat" Data.Bifoldable1.Compat as Base
+#else
+import "foldable1-classes-compat" Data.Bifoldable1 as Base
+#endif
diff --git a/base-compat-batteries/src/Data/Bifoldable1/Compat/Repl/Batteries.hs b/base-compat-batteries/src/Data/Bifoldable1/Compat/Repl/Batteries.hs
new file mode 100644
index 0000000..542d1b9
--- /dev/null
+++ b/base-compat-batteries/src/Data/Bifoldable1/Compat/Repl/Batteries.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE PackageImports #-}
+{-# OPTIONS_GHC -fno-warn-dodgy-exports -fno-warn-unused-imports #-}
+-- | Reexports "Data.Bifoldable1.Compat"
+-- from a globally unique namespace.
+module Data.Bifoldable1.Compat.Repl.Batteries (
+  module Data.Bifoldable1.Compat
+) where
+import "this" Data.Bifoldable1.Compat
diff --git a/base-compat-batteries/src/Data/Foldable1/Compat.hs b/base-compat-batteries/src/Data/Foldable1/Compat.hs
new file mode 100644
index 0000000..190a63a
--- /dev/null
+++ b/base-compat-batteries/src/Data/Foldable1/Compat.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE CPP, NoImplicitPrelude, PackageImports #-}
+module Data.Foldable1.Compat (
+  module Base
+) where
+
+#if MIN_VERSION_base(4,18,0)
+import "base-compat" Data.Foldable1.Compat as Base
+#else
+import "foldable1-classes-compat" Data.Foldable1 as Base
+#endif
diff --git a/base-compat-batteries/src/Data/Foldable1/Compat/Repl/Batteries.hs b/base-compat-batteries/src/Data/Foldable1/Compat/Repl/Batteries.hs
new file mode 100644
index 0000000..ee2a2d0
--- /dev/null
+++ b/base-compat-batteries/src/Data/Foldable1/Compat/Repl/Batteries.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE PackageImports #-}
+{-# OPTIONS_GHC -fno-warn-dodgy-exports -fno-warn-unused-imports #-}
+-- | Reexports "Data.Foldable1.Compat"
+-- from a globally unique namespace.
+module Data.Foldable1.Compat.Repl.Batteries (
+  module Data.Foldable1.Compat
+) where
+import "this" Data.Foldable1.Compat
diff --git a/base-compat-batteries/test/SafeHaskellSpec.hs b/base-compat-batteries/test/SafeHaskellSpec.hs
index 56d3006..3113940 100644
--- a/base-compat-batteries/test/SafeHaskellSpec.hs
+++ b/base-compat-batteries/test/SafeHaskellSpec.hs
@@ -14,6 +14,7 @@ import Control.Monad.Compat ()
 import Control.Monad.Fail.Compat ()
 import Control.Monad.IO.Class.Compat ()
 import Data.Bifoldable.Compat ()
+import Data.Bifoldable1.Compat ()
 import Data.Bifunctor.Compat ()
 import Data.Bitraversable.Compat ()
 import Data.Bits.Compat ()
@@ -21,6 +22,7 @@ import Data.Bool.Compat ()
 import Data.Complex.Compat ()
 import Data.Either.Compat ()
 import Data.Foldable.Compat ()
+import Data.Foldable1.Compat ()
 import Data.Function.Compat ()
 import Data.Functor.Compat ()
 import Data.Functor.Compose.Compat ()
diff --git a/base-compat/CHANGES.markdown b/base-compat/CHANGES.markdown
index a60cb82..abcc7d6 100644
--- a/base-compat/CHANGES.markdown
+++ b/base-compat/CHANGES.markdown
@@ -18,6 +18,10 @@
  - Backport `heqT` to `Data.Typeable.Compat`. Note that `heqT` is only defined
    when building with `base-4.10` or later, as that is the first version of
    `base` to provide the primitives needed to define `heqT`.
+ - Introduce `Data.Foldable1.Compat` and `Data.Bifoldable1.Compat` modules,
+   which correspond to changes made in `base-4.18.0.0`. You may consider using
+   `base-compat-batteries` instead if you want increase the range of `base`
+   versions that are supported.
 
 ## Changes in 0.12.2 [2022.08.11]
  - Sync with `base-4.17`/GHC 9.4
diff --git a/base-compat/README.markdown b/base-compat/README.markdown
index 14fa5dd..5f7ad2d 100644
--- a/base-compat/README.markdown
+++ b/base-compat/README.markdown
@@ -279,6 +279,10 @@ on, paired with the things that each library backports:
 * [`fail`](http://hackage.haskell.org/package/fail)
   for the [`MonadFail`](http://hackage.haskell.org/package/base-4.9.0.0/docs/Control-Monad-Fail.html#t:MonadFail)
   type class, introduced in `base-4.9.0.0`
+* [`foldable1-classes-compat`](https://hackage.haskell.org/package/foldable1-classes-compat)
+  for the [`Foldable1`](https://hackage.haskell.org/package/foldable1-classes-compat-0.1/docs/Data-Foldable1.html#t:Foldable1)
+  and [`Bifoldable1`](https://hackage.haskell.org/package/foldable1-classes-compat-0.1/docs/Data-Bifoldable1.html#t:Bifoldable1)
+  type classes, introduced in `base-4.18.0.0`
 * [`nats`](http://hackage.haskell.org/package/nats)
   for the [`Natural`](http://hackage.haskell.org/package/base-4.8.0.0/docs/Numeric-Natural.html)
   data type, introduced in `base-4.8.0.0`
diff --git a/base-compat/base-compat.cabal b/base-compat/base-compat.cabal
index d0f2c7f..0ac17a3 100644
--- a/base-compat/base-compat.cabal
+++ b/base-compat/base-compat.cabal
@@ -78,6 +78,7 @@ library
       Control.Monad.ST.Lazy.Unsafe.Compat
       Control.Monad.ST.Unsafe.Compat
       Data.Bifoldable.Compat
+      Data.Bifoldable1.Compat
       Data.Bifunctor.Compat
       Data.Bitraversable.Compat
       Data.Bits.Compat
@@ -85,6 +86,7 @@ library
       Data.Complex.Compat
       Data.Either.Compat
       Data.Foldable.Compat
+      Data.Foldable1.Compat
       Data.Function.Compat
       Data.Functor.Compat
       Data.Functor.Compose.Compat
@@ -142,6 +144,7 @@ library
       Control.Monad.ST.Lazy.Unsafe.Compat.Repl
       Control.Monad.ST.Unsafe.Compat.Repl
       Data.Bifoldable.Compat.Repl
+      Data.Bifoldable1.Compat.Repl
       Data.Bifunctor.Compat.Repl
       Data.Bitraversable.Compat.Repl
       Data.Bits.Compat.Repl
@@ -149,6 +152,7 @@ library
       Data.Complex.Compat.Repl
       Data.Either.Compat.Repl
       Data.Foldable.Compat.Repl
+      Data.Foldable1.Compat.Repl
       Data.Function.Compat.Repl
       Data.Functor.Compat.Repl
       Data.Functor.Compose.Compat.Repl
diff --git a/base-compat/src/Data/Bifoldable1/Compat.hs b/base-compat/src/Data/Bifoldable1/Compat.hs
new file mode 100644
index 0000000..51b9cd9
--- /dev/null
+++ b/base-compat/src/Data/Bifoldable1/Compat.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE CPP, NoImplicitPrelude #-}
+module Data.Bifoldable1.Compat (
+#if MIN_VERSION_base(4,18,0)
+  module Base
+#endif
+) where
+
+#if MIN_VERSION_base(4,18,0)
+import Data.Bifoldable1 as Base
+#endif
diff --git a/base-compat/src/Data/Bifoldable1/Compat/Repl.hs b/base-compat/src/Data/Bifoldable1/Compat/Repl.hs
new file mode 100644
index 0000000..69b230a
--- /dev/null
+++ b/base-compat/src/Data/Bifoldable1/Compat/Repl.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE PackageImports #-}
+{-# OPTIONS_GHC -fno-warn-dodgy-exports -fno-warn-unused-imports #-}
+-- | Reexports "Data.Bifoldable1.Compat"
+-- from a globally unique namespace.
+module Data.Bifoldable1.Compat.Repl (
+  module Data.Bifoldable1.Compat
+) where
+import "this" Data.Bifoldable1.Compat
diff --git a/base-compat/src/Data/Foldable1/Compat.hs b/base-compat/src/Data/Foldable1/Compat.hs
new file mode 100644
index 0000000..de2fbd1
--- /dev/null
+++ b/base-compat/src/Data/Foldable1/Compat.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE CPP, NoImplicitPrelude #-}
+module Data.Foldable1.Compat (
+#if MIN_VERSION_base(4,18,0)
+  module Base
+#endif
+) where
+
+#if MIN_VERSION_base(4,18,0)
+import Data.Foldable1 as Base
+#endif
diff --git a/base-compat/src/Data/Foldable1/Compat/Repl.hs b/base-compat/src/Data/Foldable1/Compat/Repl.hs
new file mode 100644
index 0000000..21a4d79
--- /dev/null
+++ b/base-compat/src/Data/Foldable1/Compat/Repl.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE PackageImports #-}
+{-# OPTIONS_GHC -fno-warn-dodgy-exports -fno-warn-unused-imports #-}
+-- | Reexports "Data.Foldable1.Compat"
+-- from a globally unique namespace.
+module Data.Foldable1.Compat.Repl (
+  module Data.Foldable1.Compat
+) where
+import "this" Data.Foldable1.Compat