diff --git a/test/classes/delete-free/lifetimes/bad-append-borrow.bad b/test/classes/delete-free/lifetimes/bad-append-borrow.bad
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/test/classes/delete-free/lifetimes/bad-append-borrow.future b/test/classes/delete-free/lifetimes/bad-append-borrow.future
new file mode 100644
index 000000000000..69ed750fe5ab
--- /dev/null
+++ b/test/classes/delete-free/lifetimes/bad-append-borrow.future
@@ -0,0 +1,2 @@
+Lifetime errors for list.append() stopped firing after its return type
+was changed to int in #17510.
diff --git a/test/library/standard/List/classLists/listAppendBorrow.bad b/test/library/standard/List/classLists/listAppendBorrow.bad
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/test/library/standard/List/classLists/listAppendBorrow.future b/test/library/standard/List/classLists/listAppendBorrow.future
new file mode 100644
index 000000000000..69ed750fe5ab
--- /dev/null
+++ b/test/library/standard/List/classLists/listAppendBorrow.future
@@ -0,0 +1,2 @@
+Lifetime errors for list.append() stopped firing after its return type
+was changed to int in #17510.
diff --git a/test/library/standard/List/classLists/listAppendLifetime.bad b/test/library/standard/List/classLists/listAppendLifetime.bad
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/test/library/standard/List/classLists/listAppendLifetime.future b/test/library/standard/List/classLists/listAppendLifetime.future
new file mode 100644
index 000000000000..69ed750fe5ab
--- /dev/null
+++ b/test/library/standard/List/classLists/listAppendLifetime.future
@@ -0,0 +1,2 @@
+Lifetime errors for list.append() stopped firing after its return type
+was changed to int in #17510.
diff --git a/test/library/standard/List/listAppendLifetime.bad b/test/library/standard/List/listAppendLifetime.bad
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/test/library/standard/List/listAppendLifetime.future b/test/library/standard/List/listAppendLifetime.future
new file mode 100644
index 000000000000..69ed750fe5ab
--- /dev/null
+++ b/test/library/standard/List/listAppendLifetime.future
@@ -0,0 +1,2 @@
+Lifetime errors for list.append() stopped firing after its return type
+was changed to int in #17510.