diff --git a/builtin-init-db.c b/builtin-init-db.c
index 2a20737249..31427c571d 100644
--- a/builtin-init-db.c
+++ b/builtin-init-db.c
@@ -318,9 +318,7 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	/*
 	 * Set up the default .git directory contents
 	 */
-	git_dir = getenv(GIT_DIR_ENVIRONMENT);
-	if (!git_dir)
-		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
+	git_dir = get_git_dir();
 	safe_create_dir(git_dir, 0);
 
 	/* Check to see if the repository version is right.
diff --git a/git.c b/git.c
index 1f7f595653..5fc277c895 100644
--- a/git.c
+++ b/git.c
@@ -67,14 +67,14 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
 				fprintf(stderr, "No directory given for --git-dir.\n" );
 				usage(git_usage_string);
 			}
-			setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
+			set_git_dir( (*argv)[1] );
 			if (envchanged)
 				*envchanged = 1;
 			(*argv)++;
 			(*argc)--;
 			handled++;
 		} else if (!prefixcmp(cmd, "--git-dir=")) {
-			setenv(GIT_DIR_ENVIRONMENT, cmd + 10, 1);
+			set_git_dir(cmd + 10);
 			if (envchanged)
 				*envchanged = 1;
 		} else if (!strcmp(cmd, "--work-tree")) {
@@ -93,7 +93,7 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
 				*envchanged = 1;
 		} else if (!strcmp(cmd, "--bare")) {
 			static char git_dir[PATH_MAX+1];
-			setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 1);
+			set_git_dir(getcwd(git_dir, sizeof(git_dir)));
 			if (envchanged)
 				*envchanged = 1;
 		} else {
diff --git a/path.c b/path.c
index a1139d483b..7a5ac5b067 100644
--- a/path.c
+++ b/path.c
@@ -265,7 +265,7 @@ char *enter_repo(char *path, int strict)
 
 	if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
 	    validate_headref("HEAD") == 0) {
-		setenv(GIT_DIR_ENVIRONMENT, ".", 1);
+		set_git_dir(".");
 		check_repository_format();
 		return path;
 	}
diff --git a/setup.c b/setup.c
index 5a8e7b6b52..0de8dcd61b 100644
--- a/setup.c
+++ b/setup.c
@@ -332,7 +332,7 @@ const char *setup_git_directory_gently(int *nongit_ok)
 			inside_git_dir = 1;
 			if (!work_tree_env)
 				inside_work_tree = 0;
-			setenv(GIT_DIR_ENVIRONMENT, ".", 1);
+			set_git_dir(".");
 			return NULL;
 		}
 		chdir("..");