diff --git a/lib/init/subsystem.c b/lib/init/subsystem.c
index 6e3b2318f..f850e6d7a 100644
--- a/lib/init/subsystem.c
+++ b/lib/init/subsystem.c
@@ -132,6 +132,8 @@ subsystem_sort(void)
 void
 spdk_subsystem_init_next(int rc)
 {
+	assert(spdk_get_thread() == spdk_thread_get_app_thread());
+
 	/* The initialization is interrupted by the spdk_subsystem_fini, so just return */
 	if (g_subsystems_init_interrupted) {
 		return;
@@ -167,6 +169,8 @@ spdk_subsystem_init(spdk_subsystem_init_fn cb_fn, void *cb_arg)
 {
 	struct spdk_subsystem_depend *dep;
 
+	assert(spdk_get_thread() == spdk_thread_get_app_thread());
+
 	g_subsystem_start_fn = cb_fn;
 	g_subsystem_start_arg = cb_arg;
 
diff --git a/test/unit/lib/init/subsystem.c/subsystem_ut.c b/test/unit/lib/init/subsystem.c/subsystem_ut.c
index 3197dc138..3b06f6a53 100644
--- a/test/unit/lib/init/subsystem.c/subsystem_ut.c
+++ b/test/unit/lib/init/subsystem.c/subsystem_ut.c
@@ -208,12 +208,17 @@ main(int argc, char **argv)
 {
 	CU_pSuite	suite = NULL;
 	unsigned int	num_failures;
+	struct spdk_thread *thread;
 
 	CU_set_error_action(CUEA_ABORT);
 	CU_initialize_registry();
 
 	suite = CU_add_suite("subsystem_suite", NULL, NULL);
 
+	spdk_thread_lib_init(NULL, 0);
+	thread = spdk_thread_create(NULL, NULL);
+	spdk_set_thread(thread);
+
 	CU_ADD_TEST(suite, subsystem_sort_test_depends_on_single);
 	CU_ADD_TEST(suite, subsystem_sort_test_depends_on_multiple);
 	CU_ADD_TEST(suite, subsystem_sort_test_missing_dependency);