diff --git a/exercises/practice/flower-field/.meta/tests.toml b/exercises/practice/flower-field/.meta/tests.toml
index c2b24fd..965ba8f 100644
--- a/exercises/practice/flower-field/.meta/tests.toml
+++ b/exercises/practice/flower-field/.meta/tests.toml
@@ -44,3 +44,6 @@ description = "cross"
 
 [dd9d4ca8-9e68-4f78-a677-a2a70fd7a7b8]
 description = "large garden"
+
+[6e4ac13a-3e43-4728-a2e3-3551d4b1a996]
+description = "multiple adjacent flowers"
diff --git a/exercises/practice/flower-field/test-flower-field.bats b/exercises/practice/flower-field/test-flower-field.bats
index 080ab52..9341f6b 100644
--- a/exercises/practice/flower-field/test-flower-field.bats
+++ b/exercises/practice/flower-field/test-flower-field.bats
@@ -188,3 +188,10 @@ END_EXPECTED
     assert_success
     assert_output "$expected"
 }
+
+@test "multiple adjacent flowers" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run gawk -f flower-field.awk <<< " ** "
+    assert_success
+    assert_output "1**1"
+}
diff --git a/exercises/practice/isbn-verifier/.meta/tests.toml b/exercises/practice/isbn-verifier/.meta/tests.toml
index 6d5a845..17e18d4 100644
--- a/exercises/practice/isbn-verifier/.meta/tests.toml
+++ b/exercises/practice/isbn-verifier/.meta/tests.toml
@@ -30,6 +30,12 @@ description = "invalid character in isbn is not treated as zero"
 [28025280-2c39-4092-9719-f3234b89c627]
 description = "X is only valid as a check digit"
 
+[8005b57f-f194-44ee-88d2-a77ac4142591]
+description = "only one check digit is allowed"
+
+[fdb14c99-4cf8-43c5-b06d-eb1638eff343]
+description = "X is not substituted by the value 10"
+
 [f6294e61-7e79-46b3-977b-f48789a4945b]
 description = "valid isbn without separating dashes"
 
diff --git a/exercises/practice/isbn-verifier/test-isbn-verifier.bats b/exercises/practice/isbn-verifier/test-isbn-verifier.bats
index c0f04ad..de0fa41 100644
--- a/exercises/practice/isbn-verifier/test-isbn-verifier.bats
+++ b/exercises/practice/isbn-verifier/test-isbn-verifier.bats
@@ -50,6 +50,20 @@ load bats-extra
   assert_output "false"
 }
 
+@test 'only one check digit is allowed' {
+  [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+  run gawk -f isbn-verifier.awk <<< "3-598-21508-96"
+  assert_success
+  assert_output "false"
+}
+
+@test 'X is not substituted by the value 10' {
+  [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+  run gawk -f isbn-verifier.awk <<< "3-598-2X507-5"
+  assert_success
+  assert_output "false"
+}
+
 @test "valid isbn without separating dashes" {
   [[ $BATS_RUN_SKIPPED == "true" ]] || skip
   run gawk -f isbn-verifier.awk <<< "3598215088"