diff --git a/Git.hs b/Git.hs
index b226bce0f2..168fe4154e 100644
--- a/Git.hs
+++ b/Git.hs
@@ -247,11 +247,11 @@ attributes repo
 	| configBare repo = workTree repo ++ "/info/.gitattributes"
 	| otherwise = workTree repo ++ "/.gitattributes"
 
-{- Path to a repository's .git directory, relative to its workTree. -}
+{- Path to a repository's .git directory. -}
 gitDir :: Repo -> String
 gitDir repo
-	| configBare repo = ""
-	| otherwise = ".git"
+	| configBare repo = workTree repo
+	| otherwise = workTree repo </> ".git"
 
 {- Path to a repository's --work-tree, that is, its top.
  -
@@ -345,10 +345,10 @@ urlAuthPart _ repo = assertUrl repo $ error "internal"
 
 {- Constructs a git command line operating on the specified repo. -}
 gitCommandLine :: Repo -> [CommandParam] -> [CommandParam]
-gitCommandLine repo@(Repo { location = Dir d} ) params =
+gitCommandLine repo@(Repo { location = Dir _ } ) params =
 	-- force use of specified repo via --git-dir and --work-tree
-	[ Param ("--git-dir=" ++ d ++ "/" ++ gitDir repo)
-	, Param ("--work-tree=" ++ d)
+	[ Param ("--git-dir=" ++ gitDir repo)
+	, Param ("--work-tree=" ++ workTree repo)
 	] ++ params
 gitCommandLine repo _ = assertLocal repo $ error "internal"
 
diff --git a/Init.hs b/Init.hs
index 4708701fa7..a469657a11 100644
--- a/Init.hs
+++ b/Init.hs
@@ -79,7 +79,7 @@ unlessBare a = do
 preCommitHook :: Annex FilePath
 preCommitHook = do
 	g <- Annex.gitRepo
-	return $ Git.workTree g ++ "/" ++ Git.gitDir g ++ "/hooks/pre-commit"
+	return $ Git.gitDir g ++ "/hooks/pre-commit"
 
 preCommitScript :: String
 preCommitScript = 
diff --git a/git-union-merge.hs b/git-union-merge.hs
index e763376077..4e1a932b45 100644
--- a/git-union-merge.hs
+++ b/git-union-merge.hs
@@ -20,7 +20,7 @@ usage :: IO a
 usage = error $ "bad parameters\n\n" ++ header
 
 tmpIndex :: Git.Repo -> FilePath
-tmpIndex g = Git.workTree g </> Git.gitDir g </> "index.git-union-merge"
+tmpIndex g = Git.gitDir g </> "index.git-union-merge"
 
 setup :: Git.Repo -> IO ()
 setup g = cleanup g -- idempotency