diff --git a/environment.h b/environment.h
index 123a71cdc8..9eb97b3869 100644
--- a/environment.h
+++ b/environment.h
@@ -147,8 +147,6 @@ void repo_config_values_init(struct repo_config_values *cfg);
  * Please do not add new global config variables here.
  */
 # ifdef USE_THE_REPOSITORY_VARIABLE
-void setup_git_env(const char *git_dir);
-
 /*
  * Returns true iff we have a configured git repository (either via
  * setup_git_directory, or in the environment via $GIT_DIR).
diff --git a/setup.c b/setup.c
index 796ac5792f..8965f8ccaf 100644
--- a/setup.c
+++ b/setup.c
@@ -1074,9 +1074,9 @@ static void setup_git_env_internal(struct repository *repo,
 		fetch_if_missing = 0;
 }
 
-void setup_git_env(const char *git_dir)
+static void setup_git_env(struct repository *repo, const char *git_dir)
 {
-	setup_git_env_internal(the_repository, git_dir, false);
+	setup_git_env_internal(repo, git_dir, false);
 }
 
 static void set_git_dir_1(struct repository *repo, const char *path, bool skip_initializing_odb)
@@ -1988,7 +1988,7 @@ const char *setup_git_directory_gently(int *nongit_ok)
 			const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
 			if (!gitdir)
 				gitdir = DEFAULT_GIT_DIR_ENVIRONMENT;
-			setup_git_env(gitdir);
+			setup_git_env(the_repository, gitdir);
 		}
 		if (startup_info->have_repository) {
 			repo_set_hash_algo(the_repository, repo_fmt.hash_algo);