diff --git a/Cabal.cabal b/Cabal.cabal
--- a/Cabal.cabal
+++ b/Cabal.cabal
@@ -1,6 +1,6 @@
 cabal-version: >=1.10
 name:          Cabal
-version:       3.4.0.0
+version:       3.4.1.0
 copyright:     2003-2020, Cabal Development Team (see AUTHORS file)
 license:       BSD3
 license-file:  LICENSE
@@ -705,7 +705,7 @@
     filepath,
     integer-logarithms >= 1.0.2 && <1.1,
     pretty,
-    rere >=0.1 && <0.2,
+    rere >=0.1 && <0.3,
     tagged,
     tasty >= 1.2.3 && < 1.4,
     tasty-hunit,
diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,4 +1,7 @@
-# 3.4.0.0 [Oleg Grenrus](mailgo:oleg.grnerus@iki.fi) February 2021
+# 3.4.1.0 [Emily Pillmore](mailto:emilypi@cohomolo.gy) October 2021
+  * See https://github.com/haskell/cabal/blob/master/release-notes/Cabal-3.4.1.0.md
+
+# 3.4.0.0 [Oleg Grenrus](mailto:oleg.grnerus@iki.fi) February 2021
   * See https://github.com/haskell/cabal/blob/master/release-notes/Cabal-3.4.0.0.md
 
 # 3.2.1.0 [Oleg Grenrus](mailto:oleg.grenris@iki.fi) October 2020
@@ -6,7 +9,7 @@
   * Use process jobs when calling subprocesses
   * Require custom-setup for `cabal-version: 1.24` and later
   * Accept `linux-androideabi` as an alias for Android
-  * Fix ghci being launched before other sources are built 
+  * Fix ghci being launched before other sources are built
   * Require cabal-versions >=1.25 to be exact
 
 # 3.2.0.0 [Herbert Valerio Riedel](mailto:hvr@gnu.org) April 2020
diff --git a/Distribution/Simple.hs b/Distribution/Simple.hs
--- a/Distribution/Simple.hs
+++ b/Distribution/Simple.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE CPP #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Distribution.Simple
@@ -98,7 +99,11 @@
 import System.Environment (getArgs, getProgName)
 import System.Directory   (removeFile, doesFileExist
                           ,doesDirectoryExist, removeDirectoryRecursive)
-import System.FilePath                      (searchPathSeparator, takeDirectory, (</>), splitDirectories, dropDrive)
+import System.FilePath    (searchPathSeparator, takeDirectory, (</>),
+                           splitDirectories, dropDrive)
+#ifdef mingw32_HOST_OS
+import System.FilePath    (normalise, splitDrive)
+#endif
 import Distribution.Compat.ResponseFile (expandResponse)
 import Distribution.Compat.Directory        (makeAbsolute)
 import Distribution.Compat.Environment      (getEnvironment)
@@ -717,7 +722,7 @@
   -- TODO: We don't check for colons, tildes or leading dashes. We
   -- also should check the builddir's path, destdir, and all other
   -- paths as well.
-  let configureFile' = intercalate "/" $ splitDirectories configureFile
+  let configureFile' = toUnix configureFile
   for_ badAutoconfCharacters $ \(c, cname) ->
     when (c `elem` dropDrive configureFile') $
       warn verbosity $ concat
@@ -756,6 +761,19 @@
                ++ "Unix compatibility toolchain such as MinGW+MSYS or Cygwin. "
                ++ "If you are not on Windows, ensure that an 'sh' command "
                ++ "is discoverable in your path."
+
+-- | Convert Windows path to Unix ones
+toUnix :: String -> String
+#ifdef mingw32_HOST_OS
+toUnix s = let tmp = normalise s
+               (l, rest) = case splitDrive tmp of
+                             ([],  x) -> ("/"      , x)
+                             (h:_, x) -> ('/':h:"/", x)
+               parts = splitDirectories rest
+           in  l ++ intercalate "/" parts
+#else
+toUnix s = intercalate "/" $ splitDirectories s
+#endif
 
 badAutoconfCharacters :: [(Char, String)]
 badAutoconfCharacters =