diff --git a/GHC/BaseDir.hs b/GHC/BaseDir.hs
--- a/GHC/BaseDir.hs
+++ b/GHC/BaseDir.hs
@@ -12,7 +12,11 @@
 -- installation location at build time. ghc-pkg also can expand those variables
 -- and so needs the top dir location to do that too.
 
-module GHC.BaseDir where
+module GHC.BaseDir
+  ( expandTopDir
+  , expandPathVar
+  , getBaseDir
+  ) where
 
 import Prelude -- See Note [Why do we import Prelude here?]
 
@@ -20,11 +24,9 @@
 import Data.Maybe (listToMaybe)
 import System.FilePath
 
--- Windows
-#if defined(mingw32_HOST_OS)
-import System.Environment (getExecutablePath)
--- POSIX
-#elif defined(darwin_HOST_OS) || defined(linux_HOST_OS) || defined(freebsd_HOST_OS) || defined(openbsd_HOST_OS) || defined(netbsd_HOST_OS)
+#if MIN_VERSION_base(4,17,0) && !defined(openbsd_HOST_OS)
+import System.Environment (executablePath)
+#else
 import System.Environment (getExecutablePath)
 #endif
 
@@ -43,17 +45,29 @@
 expandPathVar var value (x:xs) = x : expandPathVar var value xs
 expandPathVar _ _ [] = []
 
+#if !MIN_VERSION_base(4,17,0) || defined(openbsd_HOST_OS)
+-- Polyfill for base-4.17 executablePath and OpenBSD which doesn't
+-- have executablePath. The best it can do is use argv[0] which is
+-- good enough for most uses of getBaseDir.
+executablePath :: Maybe (IO (Maybe FilePath))
+executablePath = Just (Just <$> getExecutablePath)
+#elif !MIN_VERSION_base(4,18,0) && defined(js_HOST_ARCH)
+-- executablePath is missing from base < 4.18.0 on js_HOST_ARCH
+executablePath :: Maybe (IO (Maybe FilePath))
+executablePath = Nothing
+#endif
+
 -- | Calculate the location of the base dir
 getBaseDir :: IO (Maybe String)
 #if defined(mingw32_HOST_OS)
-getBaseDir = Just . (\p -> p </> "lib") . rootDir <$> getExecutablePath
+getBaseDir = maybe (pure Nothing) ((((</> "lib") . rootDir) <$>) <$>) executablePath
   where
     -- locate the "base dir" when given the path
     -- to the real ghc executable (as opposed to symlink)
     -- that is running this function.
     rootDir :: FilePath -> FilePath
     rootDir = takeDirectory . takeDirectory . normalise
-#elif defined(darwin_HOST_OS) || defined(linux_HOST_OS) || defined(freebsd_HOST_OS) || defined(openbsd_HOST_OS) || defined(netbsd_HOST_OS)
+#else
 -- on unix, this is a bit more confusing.
 -- The layout right now is something like
 --
@@ -65,14 +79,15 @@
 -- As such, we first need to find the absolute location to the
 -- binary.
 --
--- getExecutablePath will return (3). One takeDirectory will
+-- executablePath will return (3). One takeDirectory will
 -- give use /lib/ghc-X.Y.Z/bin, and another will give us (4).
 --
 -- This of course only works due to the current layout. If
 -- the layout is changed, such that we have ghc-X.Y.Z/{bin,lib}
 -- this would need to be changed accordingly.
 --
-getBaseDir = Just . (\p -> p </> "lib") . takeDirectory . takeDirectory <$> getExecutablePath
-#else
-getBaseDir = return Nothing
+getBaseDir = maybe (pure Nothing) ((((</> "lib") . rootDir) <$>) <$>) executablePath
+  where
+    rootDir :: FilePath -> FilePath
+    rootDir = takeDirectory . takeDirectory
 #endif
diff --git a/ghc-boot.cabal b/ghc-boot.cabal
--- a/ghc-boot.cabal
+++ b/ghc-boot.cabal
@@ -5,7 +5,7 @@
 -- ghc-boot.cabal.
 
 name:           ghc-boot
-version:        9.6.6
+version:        9.8.1
 license:        BSD-3-Clause
 license-file:   LICENSE
 category:       GHC
@@ -70,14 +70,14 @@
             GHC.Version
             GHC.Platform.Host
 
-    build-depends: base       >= 4.7 && < 4.19,
+    build-depends: base       >= 4.7 && < 4.20,
                    binary     == 0.8.*,
-                   bytestring >= 0.10 && < 0.12,
+                   bytestring >= 0.10 && < 0.13,
                    containers >= 0.5 && < 0.7,
                    directory  >= 1.2 && < 1.4,
                    filepath   >= 1.3 && < 1.5,
-                   deepseq    >= 1.4 && < 1.5,
-                   ghc-boot-th == 9.6.6
+                   deepseq    >= 1.4 && < 1.6,
+                   ghc-boot-th == 9.8.1
     if !os(windows)
         build-depends:
                    unix       >= 2.7 && < 2.9