diff --git a/t/lib-sudo.sh b/t/lib-sudo.sh
new file mode 100644
index 0000000000..b4d7788f4e
--- /dev/null
+++ b/t/lib-sudo.sh
@@ -0,0 +1,15 @@
+# Helpers for running git commands under sudo.
+
+# Runs a scriplet passed through stdin under sudo.
+run_with_sudo () {
+	local ret
+	local RUN="$TEST_DIRECTORY/$$.sh"
+	write_script "$RUN" "$TEST_SHELL_PATH"
+	# avoid calling "$RUN" directly so sudo doesn't get a chance to
+	# override the shell, add aditional restrictions or even reject
+	# running the script because its security policy deem it unsafe
+	sudo "$TEST_SHELL_PATH" -c "\"$RUN\""
+	ret=$?
+	rm -f "$RUN"
+	return $ret
+}
diff --git a/t/t0034-root-safe-directory.sh b/t/t0034-root-safe-directory.sh
index 6b8ea5357f..a621f1ea5e 100755
--- a/t/t0034-root-safe-directory.sh
+++ b/t/t0034-root-safe-directory.sh
@@ -3,6 +3,7 @@
 test_description='verify safe.directory checks while running as root'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-sudo.sh
 
 if [ "$GIT_TEST_ALLOW_SUDO" != "YES" ]
 then
@@ -10,6 +11,12 @@ then
 	test_done
 fi
 
+if ! test_have_prereq NOT_ROOT
+then
+	skip_all="These tests do not support running as root"
+	test_done
+fi
+
 test_lazy_prereq SUDO '
 	sudo -n id -u >u &&
 	id -u root >r &&
@@ -19,6 +26,12 @@ test_lazy_prereq SUDO '
 	test_cmp u r
 '
 
+if ! test_have_prereq SUDO
+then
+	skip_all="Your sudo/system configuration is either too strict or unsupported"
+	test_done
+fi
+
 test_expect_success SUDO 'setup' '
 	sudo rm -rf root &&
 	mkdir -p root/r &&
@@ -36,6 +49,55 @@ test_expect_success SUDO 'sudo git status as original owner' '
 	)
 '
 
+test_expect_success SUDO 'setup root owned repository' '
+	sudo mkdir -p root/p &&
+	sudo git init root/p
+'
+
+test_expect_success 'cannot access if owned by root' '
+	(
+		cd root/p &&
+		test_must_fail git status
+	)
+'
+
+test_expect_success 'can access if addressed explicitly' '
+	(
+		cd root/p &&
+		GIT_DIR=.git GIT_WORK_TREE=. git status
+	)
+'
+
+test_expect_failure SUDO 'can access with sudo if root' '
+	(
+		cd root/p &&
+		sudo git status
+	)
+'
+
+test_expect_success SUDO 'can access with sudo if root by removing SUDO_UID' '
+	(
+		cd root/p &&
+		run_with_sudo <<-END
+			unset SUDO_UID &&
+			git status
+		END
+	)
+'
+
+test_lazy_prereq SUDO_SUDO '
+	sudo sudo id -u >u &&
+	id -u root >r &&
+	test_cmp u r
+'
+
+test_expect_success SUDO_SUDO 'can access with sudo abusing SUDO_UID' '
+	(
+		cd root/p &&
+		sudo sudo git status
+	)
+'
+
 # this MUST be always the last test
 test_expect_success SUDO 'cleanup' '
 	sudo rm -rf root