diff --git a/Documentation/config/safe.txt b/Documentation/config/safe.txt
index 63597b2df8f80f..6d764fe0ccf3a8 100644
--- a/Documentation/config/safe.txt
+++ b/Documentation/config/safe.txt
@@ -19,3 +19,10 @@ line option `-c safe.directory=<path>`.
 The value of this setting is interpolated, i.e. `~/<path>` expands to a
 path relative to the home directory and `%(prefix)/<path>` expands to a
 path relative to Git's (runtime) prefix.
++
+To completely opt-out of this security check, set `safe.directory` to the
+string `*`. This will allow all repositories to be treated as if their
+directory was listed in the `safe.directory` list. If `safe.directory=*`
+is set in system config and you want to re-enable this protection, then
+initialize your list with an empty value before listing the repositories
+that you deem safe.
diff --git a/setup.c b/setup.c
index c8f67bfed5206f..a42b21307f7708 100644
--- a/setup.c
+++ b/setup.c
@@ -1100,9 +1100,14 @@ static int safe_directory_cb(const char *key, const char *value, void *d)
 {
 	struct safe_directory_data *data = d;
 
-	if (!value || !*value)
+	if (strcmp(key, "safe.directory"))
+		return 0;
+
+	if (!value || !*value) {
 		data->is_safe = 0;
-	else {
+	} else if (!strcmp(value, "*")) {
+		data->is_safe = 1;
+	} else {
 		const char *interpolated = NULL;
 
 		if (!git_config_pathname(&interpolated, key, value) &&
@@ -1119,7 +1124,8 @@ static int ensure_valid_ownership(const char *path)
 {
 	struct safe_directory_data data = { .path = path };
 
-	if (is_path_owned_by_current_user(path))
+	if (is_path_owned_by_current_user(path) &&
+	    !git_env_bool("GIT_TEST_ASSUME_DIFFERENT_OWNER", 0))
 		return 1;
 
 	read_very_early_config(safe_directory_cb, &data);
diff --git a/t/t0033-safe-directory.sh b/t/t0033-safe-directory.sh
new file mode 100755
index 00000000000000..239d93f4d21141
--- /dev/null
+++ b/t/t0033-safe-directory.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+
+test_description='verify safe.directory checks'
+
+. ./test-lib.sh
+
+GIT_TEST_ASSUME_DIFFERENT_OWNER=1
+export GIT_TEST_ASSUME_DIFFERENT_OWNER
+
+expect_rejected_dir () {
+	test_must_fail git status 2>err &&
+	grep "safe.directory" err
+}
+
+test_expect_success 'safe.directory is not set' '
+	expect_rejected_dir
+'
+
+test_expect_success 'safe.directory does not match' '
+	git config --global safe.directory bogus &&
+	expect_rejected_dir
+'
+
+test_expect_success 'path exist as different key' '
+	git config --global foo.bar "$(pwd)" &&
+	expect_rejected_dir
+'
+
+test_expect_success 'safe.directory matches' '
+	git config --global --add safe.directory "$(pwd)" &&
+	git status
+'
+
+test_expect_success 'safe.directory matches, but is reset' '
+	git config --global --add safe.directory "" &&
+	expect_rejected_dir
+'
+
+test_expect_success 'safe.directory=*' '
+	git config --global --add safe.directory "*" &&
+	git status
+'
+
+test_expect_success 'safe.directory=*, but is reset' '
+	git config --global --add safe.directory "" &&
+	expect_rejected_dir
+'
+
+test_done