diff --git a/vlib/v/tests/generics/generic_as_cast_on_map_test.v b/vlib/v/tests/generics/generic_as_cast_on_map_test.v
new file mode 100644
index 00000000000000..15393be045f806
--- /dev/null
+++ b/vlib/v/tests/generics/generic_as_cast_on_map_test.v
@@ -0,0 +1,14 @@
+type Sumtype = string | int
+
+fn generic_fn[T](x Sumtype) bool {
+	y := [x].map(it as T)
+	mut arr := []T{}
+	arr << x as T
+	dump(arr)
+	return arr.contains(y[0])
+}
+
+fn test_main() {
+	assert generic_fn[string]('hello')
+	assert generic_fn[int](123)
+}