diff --git a/tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions01.ts b/tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions01.ts
new file mode 100644
index 00000000000..2f3da304c99
--- /dev/null
+++ b/tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions01.ts
@@ -0,0 +1,3 @@
+// @declaration: true
+
+let x = <{a: number; a: number}>{};
\ No newline at end of file
diff --git a/tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions02.ts b/tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions02.ts
new file mode 100644
index 00000000000..265fdbe5321
--- /dev/null
+++ b/tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions02.ts
@@ -0,0 +1,3 @@
+// @declaration: true
+
+let x = {} as {a: number; a: number};
\ No newline at end of file