diff --git a/c-check/test_normal.c b/c-check/test_normal.c
index acf0e0b8..30332830 100644
--- a/c-check/test_normal.c
+++ b/c-check/test_normal.c
@@ -46,6 +46,16 @@ START_TEST(normalitem_whenSellInNegative_decreasesByTwo)
 }
 END_TEST
 
+START_TEST(normalitem_whenSellInZero_decreasesByTwo)
+{
+  Item items[1];
+  init_item(items, NORMAL_ITEM, -1, 15);
+  update_quality(items, 1);
+
+  ck_assert_int_eq(13, items[0].quality);
+}
+END_TEST
+
 TCase *tcase_normal(void)
 {
   TCase *tc;
@@ -55,6 +65,7 @@ TCase *tcase_normal(void)
   tcase_add_test(tc, normalitem_whenSellIsZero_decreasesQualityByTwo);
   tcase_add_test(tc, normalitem_whenQualityZero_doesNotDecrease);
   tcase_add_test(tc, normalitem_whenSellInNegative_decreasesByTwo);
+  tcase_add_test(tc, normalitem_whenSellInZero_decreasesByTwo);
 
   return tc;
 }