diff --git a/fs-api/fs-api.cabal b/fs-api/fs-api.cabal
index 3dca031..60e8a70 100644
--- a/fs-api/fs-api.cabal
+++ b/fs-api/fs-api.cabal
@@ -42,12 +42,6 @@ library
                     , Util.CallStack
                     , Util.Condense
 
-  if os(windows)
-    exposed-modules:
-                      -- TODO Delete this module once all our projects have upgraded to at least
-                      -- ghc-8.10.7, but not before
-                      System.IO.Seek
-
   default-language:   Haskell2010
 
   build-depends:      base        >=4.14  && <4.17
diff --git a/fs-api/src-win32/System/IO/Seek.hsc b/fs-api/src-win32/System/IO/Seek.hsc
deleted file mode 100644
index 1957864..0000000
--- a/fs-api/src-win32/System/IO/Seek.hsc
+++ /dev/null
@@ -1,29 +0,0 @@
-{-# LANGUAGE Safe #-}
-
--- The code of this module is copied from https://github.com/haskell/win32.
--- setFilePointerEx was introduced in Win32 in version 2.6.2.0, but katip
--- does not allow us to use it.
-
-module System.IO.Seek
-  ( setFilePointerEx
-  ) where
-
-#include <windows.h>
-
-import           System.Win32.Types
-import           System.Win32.File (FilePtrDirection)
-import           Foreign (Ptr, alloca, peek)
-
-setFilePointerEx :: HANDLE -> LARGE_INTEGER -> FilePtrDirection -> IO LARGE_INTEGER
-setFilePointerEx h dist dir =
-  alloca $ \p_pos -> do
-  failIfFalse_ "SetFilePointerEx" $ c_SetFilePointerEx h dist p_pos dir
-  peek p_pos
-#if defined(i386_HOST_ARCH)
-foreign import stdcall unsafe "windows.h SetFilePointerEx"
-#elif defined(x86_64_HOST_ARCH)
-foreign import ccall unsafe "windows.h SetFilePointerEx"
-#else
-# error Unknown mingw32 arch
-#endif
-  c_SetFilePointerEx :: HANDLE -> LARGE_INTEGER -> Ptr LARGE_INTEGER -> FilePtrDirection -> IO Bool