diff --git a/exercises/practice/change/.meta/tests.toml b/exercises/practice/change/.meta/tests.toml
index 5428601..b9e9ee1 100644
--- a/exercises/practice/change/.meta/tests.toml
+++ b/exercises/practice/change/.meta/tests.toml
@@ -26,6 +26,9 @@ description = "possible change without unit coins available"
 [9a166411-d35d-4f7f-a007-6724ac266178]
 description = "another possible change without unit coins available"
 
+[ce0f80d5-51c3-469d-818c-3e69dbd25f75]
+description = "a greedy approach is not optimal"
+
 [bbbcc154-e9e9-4209-a4db-dd6d81ec26bb]
 description = "no coins make 0 change"
 
diff --git a/exercises/practice/change/run_test.v b/exercises/practice/change/run_test.v
index 2011153..298e724 100644
--- a/exercises/practice/change/run_test.v
+++ b/exercises/practice/change/run_test.v
@@ -33,6 +33,10 @@ fn test_another_possible_change_without_unit_coins_available() {
 	assert find_fewest_coins([4, 5], 27)! == [4, 4, 4, 5, 5, 5]
 }
 
+fn test_a_greedy_approach_is_not_optimal() {
+	assert find_fewest_coins([1, 10, 11], 20)! == [10, 10]
+}
+
 fn test_no_coins_make_0_change() {
 	assert find_fewest_coins([1, 5, 10, 21, 25], 0)! == []
 }
diff --git a/exercises/practice/knapsack/.meta/tests.toml b/exercises/practice/knapsack/.meta/tests.toml
index 5a7805b..44e9347 100644
--- a/exercises/practice/knapsack/.meta/tests.toml
+++ b/exercises/practice/knapsack/.meta/tests.toml
@@ -4,6 +4,11 @@
 
 [a4d7d2f0-ad8a-460c-86f3-88ba709d41a7]
 description = "no items"
+include = false
+
+[3993a824-c20e-493d-b3c9-ee8a7753ee59]
+description = "no items"
+reimplements = "a4d7d2f0-ad8a-460c-86f3-88ba709d41a7"
 
 [1d39e98c-6249-4a8b-912f-87cb12e506b0]
 description = "one item, too heavy"
diff --git a/exercises/practice/roman-numerals/.meta/tests.toml b/exercises/practice/roman-numerals/.meta/tests.toml
index c92ccc5..0345244 100644
--- a/exercises/practice/roman-numerals/.meta/tests.toml
+++ b/exercises/practice/roman-numerals/.meta/tests.toml
@@ -77,5 +77,8 @@ description = "3000 is MMM"
 [3bc4b41c-c2e6-49d9-9142-420691504336]
 description = "3001 is MMMI"
 
+[2f89cad7-73f6-4d1b-857b-0ef531f68b7e]
+description = "3888 is MMMDCCCLXXXVIII"
+
 [4e18e96b-5fbb-43df-a91b-9cb511fe0856]
 description = "3999 is MMMCMXCIX"
diff --git a/exercises/practice/roman-numerals/run_test.v b/exercises/practice/roman-numerals/run_test.v
index 03d9595..88c834d 100644
--- a/exercises/practice/roman-numerals/run_test.v
+++ b/exercises/practice/roman-numerals/run_test.v
@@ -100,6 +100,10 @@ fn test_3001_is_mmmi() {
 	assert roman(3001) == 'MMMI'
 }
 
+fn test_3888_is_mmmdccclxxxviii() {
+	assert roman(3888) == 'MMMDCCCLXXXVIII'
+}
+
 fn test_3999_is_mmmcmxcix() {
 	assert roman(3999) == 'MMMCMXCIX'
 }