diff --git a/tests/fsm/fsm_dealloc_test.c b/tests/fsm/fsm_dealloc_test.c
index 9a6974d..48f80e5 100644
--- a/tests/fsm/fsm_dealloc_test.c
+++ b/tests/fsm/fsm_dealloc_test.c
@@ -452,7 +452,7 @@
 
 	log_set_category_filter(osmo_stderr_target, DLGLOBAL, 1, LOGL_DEBUG);
 
-	osmo_fsm_register(&test_fsm);
+	OSMO_ASSERT(osmo_fsm_register(&test_fsm) == 0);
 
 	test_osmo_fsm_term_safely();
 	test_osmo_fsm_set_dealloc_ctx();
diff --git a/tests/fsm/fsm_test.c b/tests/fsm/fsm_test.c
index f8ebdc7..911aad8 100644
--- a/tests/fsm/fsm_test.c
+++ b/tests/fsm/fsm_test.c
@@ -417,7 +417,7 @@
 
 	g_ctx = NULL;
 	OSMO_ASSERT(osmo_fsm_find_by_name(fsm.name) == NULL);
-	osmo_fsm_register(&fsm);
+	OSMO_ASSERT(osmo_fsm_register(&fsm) == 0);
 	OSMO_ASSERT(osmo_fsm_find_by_name(fsm.name) == &fsm);
 
 	OSMO_ASSERT(osmo_fsm_inst_find_by_name(&fsm, "my_id") == NULL);
diff --git a/tests/tdef/tdef_test.c b/tests/tdef/tdef_test.c
index 276330a..9c0808e 100644
--- a/tests/tdef/tdef_test.c
+++ b/tests/tdef/tdef_test.c
@@ -475,7 +475,7 @@
 	log_set_print_category(osmo_stderr_target, 1);
 	log_set_use_color(osmo_stderr_target, 0);
 
-	osmo_fsm_register(&test_tdef_fsm);
+	OSMO_ASSERT(osmo_fsm_register(&test_tdef_fsm) == 0);
 
 	test_tdef_get(argc > 1);
 	test_tdef_get_nonexisting();
diff --git a/tests/use_count/use_count_test.c b/tests/use_count/use_count_test.c
index 0b081c9..95af308 100644
--- a/tests/use_count/use_count_test.c
+++ b/tests/use_count/use_count_test.c
@@ -331,7 +331,7 @@
 	log_set_print_level(osmo_stderr_target, 1);
 	log_set_use_color(osmo_stderr_target, 0);
 
-	osmo_fsm_register(&foo_fsm);
+	OSMO_ASSERT(osmo_fsm_register(&foo_fsm) == 0);
 
 	test_use_count_fsm();