diff --git a/gitrev.cabal b/gitrev.cabal
--- a/gitrev.cabal
+++ b/gitrev.cabal
@@ -1,5 +1,5 @@
 name:                gitrev
-version:             1.2.0
+version:             1.3.0
 synopsis:            Compile git revision info into Haskell projects
 homepage:            https://github.com/acfoltzer/gitrev
 license:             BSD3
@@ -9,6 +9,7 @@
 category:            Development
 build-type:          Simple
 cabal-version:       >=1.10
+tested-with:         GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3, GHC == 8.0.2
 description:         Some handy Template Haskell splices for including the current git hash and branch in the code of your project. Useful for including in panic messages, @--version@ output, or diagnostic info for more informative bug reports.
 
 source-repository head
@@ -17,10 +18,12 @@
 
 library
   build-depends:       base >= 4.6 && < 5,
+                       base-compat >= 0.6.0,
                        directory,
                        filepath,
                        template-haskell,
                        process
   hs-source-dirs:      src
+  ghc-options:         -Wall
   default-language:    Haskell2010
   exposed-modules:     Development.GitRev
diff --git a/src/Development/GitRev.hs b/src/Development/GitRev.hs
--- a/src/Development/GitRev.hs
+++ b/src/Development/GitRev.hs
@@ -1,3 +1,6 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE MultiWayIf #-}
+
 -- |
 -- Module      :  $Header$
 -- Copyright   :  (c) 2015 Adam C. Foltzer
@@ -31,7 +34,6 @@
 
 module Development.GitRev (gitHash, gitBranch, gitDirty, gitCommitCount, gitCommitDate) where
 
-import Control.Applicative
 import Control.Exception
 import Control.Monad
 import Data.Maybe
@@ -42,6 +44,9 @@
 import System.FilePath
 import System.Process
 
+import Prelude ()
+import Prelude.Compat
+
 -- | Run git with the given arguments and no stdin, returning the
 -- stdout output. If git isn't available or something goes wrong,
 -- return the second argument.
@@ -53,7 +58,7 @@
   if gitFound
     then do
       -- a lot of bookkeeping to record the right dependencies
-      pwd <- runIO getCurrentDirectory
+      pwd <- runIO getGitDirectory
       let hd         = pwd </> ".git" </> "HEAD"
           index      = pwd </> ".git" </> "index"
           packedRefs = pwd </> ".git" </> "packed-refs"
@@ -61,8 +66,7 @@
       when hdExists $ do
         -- the HEAD file either contains the hash of a detached head
         -- or a pointer to the file that contains the hash of the head
-        hdRef <- runIO $ readFile hd
-        case splitAt 5 hdRef of
+        splitAt 5 `fmap` runIO (readFile hd) >>= \case
           -- pointer to ref
           ("ref: ", relRef) -> do
             let ref = pwd </> ".git" </> relRef
@@ -84,6 +88,26 @@
           ExitSuccess   -> return (takeWhile (/= '\n') out)
           ExitFailure _ -> return def
     else return def
+
+-- | Determine where our git directory is, in case we're in a
+-- submodule.
+getGitDirectory :: IO FilePath
+getGitDirectory = do
+  pwd <- getCurrentDirectory
+  let dotGit = pwd </> ".git"
+      oops = return dotGit -- it's gonna fail, that's fine
+  isDir <- doesDirectoryExist dotGit
+  isFile <- doesFileExist dotGit
+  if | isDir -> return dotGit
+     | not isFile -> oops
+     | isFile ->
+         splitAt 8 `fmap` readFile dotGit >>= \case
+           ("gitdir: ", relDir) -> do
+             isRelDir <- doesDirectoryExist relDir
+             if isRelDir
+               then return relDir
+               else oops
+           _ -> oops
 
 -- | Type to flag if the git index is used or not in a call to runGit
 data IndexUsed = IdxUsed -- ^ The git index is used