diff --git a/Libraries/LibJS/Tests/builtins/Function/Function.prototype.@@hasInstance.js b/Libraries/LibJS/Tests/builtins/Function/Function.prototype.@@hasInstance.js
new file mode 100644
index 0000000000..d548a635fe
--- /dev/null
+++ b/Libraries/LibJS/Tests/builtins/Function/Function.prototype.@@hasInstance.js
@@ -0,0 +1,8 @@
+test("basic functionality", () => {
+    expect(Function.prototype[Symbol.hasInstance]).toHaveLength(1);
+
+    function Foo() {}
+    const foo = new Foo();
+
+    expect(Function.prototype[Symbol.hasInstance].call(Foo, foo)).toBeTrue();
+});
diff --git a/Libraries/LibJS/Tests/custom-@@hasInstance.js b/Libraries/LibJS/Tests/custom-@@hasInstance.js
new file mode 100644
index 0000000000..2540beaf68
--- /dev/null
+++ b/Libraries/LibJS/Tests/custom-@@hasInstance.js
@@ -0,0 +1,9 @@
+test("basic functionality", () => {
+    function Foo() {}
+    Foo[Symbol.hasInstance] = value => {
+        return value === 2;
+    };
+
+    expect(new Foo() instanceof Foo).toBeFalse();
+    expect(2 instanceof Foo).toBeTrue();
+});