diff --git a/repository/Grease-Tests-Core.package/GRCollectionTest.class/instance/assert.validSequencedResponseFrom..st b/repository/Grease-Tests-Core.package/GRCollectionTest.class/instance/assert.validSequencedResponseFrom..st
new file mode 100644
index 00000000..98b858fd
--- /dev/null
+++ b/repository/Grease-Tests-Core.package/GRCollectionTest.class/instance/assert.validSequencedResponseFrom..st
@@ -0,0 +1,5 @@
+asserting
+assert: responseCollection validSequencedResponseFrom: receiverCollection
+	"Assert that the returned object is of a valid response class for the tested collection."
+	
+	self assert: (self isValidNewSequencedResponseClass: responseCollection class)
\ No newline at end of file
diff --git a/repository/Grease-Tests-Core.package/GRIntervalTest.class/instance/testSorted.st b/repository/Grease-Tests-Core.package/GRIntervalTest.class/instance/testSorted.st
new file mode 100644
index 00000000..b7b0ada5
--- /dev/null
+++ b/repository/Grease-Tests-Core.package/GRIntervalTest.class/instance/testSorted.st
@@ -0,0 +1,12 @@
+tests
+testSorted
+	"Unlike super implementation do not assume Interval >> #sorted returns a new object"
+	| sorted collection |
+	collection := self arbitraryCollection.
+	sorted := collection sorted.
+	self assert: sorted validSequencedResponseFrom: collection.
+	self assert: sorted sortedWith: [ :a :b | a <= b ].
+	
+	sorted := collection sorted: [ :a :b | a > b ].
+	self assert: sorted validSequencedNewResponseFrom: collection.
+	self assert: sorted sortedWith: [ :a :b | a > b ]
\ No newline at end of file