diff --git a/tests/cases/conformance/jsdoc/jsdocIndexSignature.ts b/tests/cases/conformance/jsdoc/jsdocIndexSignature.ts
index fdf9e06e61e..29365cb91be 100644
--- a/tests/cases/conformance/jsdoc/jsdocIndexSignature.ts
+++ b/tests/cases/conformance/jsdoc/jsdocIndexSignature.ts
@@ -8,3 +8,8 @@ var o1;
 var o2;
 /** @type {Object.<boolean, string>} */
 var o3;
+/** @param {Object.<string, boolean>} o */
+function f(o) {
+    o.foo = 1; // error
+    o.bar = false; // ok
+}