diff --git a/lib/test_objagg.c b/lib/test_objagg.c
index 3dd4577..72c1abf 100644
--- a/lib/test_objagg.c
+++ b/lib/test_objagg.c
@@ -745,8 +745,10 @@ static int check_expect_stats(struct objagg *objagg,
 	int err;
 
 	stats = objagg_stats_get(objagg);
-	if (IS_ERR(stats))
+	if (IS_ERR(stats)) {
+		*errmsg = "objagg_stats_get() failed.";
 		return PTR_ERR(stats);
+	}
 	err = __check_expect_stats(stats, expect_stats, errmsg);
 	objagg_stats_put(stats);
 	return err;
@@ -786,7 +788,6 @@ static int test_delta_action_item(struct world *world,
 	if (err)
 		goto errout;
 
-	errmsg = NULL;
 	err = check_expect_stats(objagg, &action_item->expect_stats, &errmsg);
 	if (err) {
 		pr_err("Key %u: Stats: %s\n", action_item->key_id, errmsg);