diff --git a/tests/cases/conformance/types/typeRelationships/comparable/optionalProperties01.ts b/tests/cases/conformance/types/typeRelationships/comparable/optionalProperties01.ts
new file mode 100644
index 00000000000..d4f04d78c80
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/comparable/optionalProperties01.ts
@@ -0,0 +1,11 @@
+// @strictNullChecks: true
+// @declaration: true
+
+interface Foo {
+  required1: string;
+  required2: string;
+  optional?: string;
+}
+
+const foo1 = { required1: "hello" } as Foo;
+const foo2 = { required1: "hello", optional: "bar" } as Foo;
diff --git a/tests/cases/conformance/types/typeRelationships/comparable/optionalProperties02.ts b/tests/cases/conformance/types/typeRelationships/comparable/optionalProperties02.ts
new file mode 100644
index 00000000000..21f83276d44
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/comparable/optionalProperties02.ts
@@ -0,0 +1,9 @@
+// @strictNullChecks: true
+// @declaration: true
+
+interface Foo {
+    a?: string;
+    b: string;
+}
+
+<Foo>{ a: undefined };
\ No newline at end of file