diff --git a/tests/pos/i15786.scala b/tests/pos/i15786.scala
new file mode 100644
index 000000000000..8c9b605d9c3d
--- /dev/null
+++ b/tests/pos/i15786.scala
@@ -0,0 +1,15 @@
+class A(val f: () => Int) {
+  def mA(p: Int = 0): Int = p
+}
+
+trait B {
+  def mB(p1: Int): Unit
+}
+
+class C[T](val f1: B, val f2: T)
+
+val f = new A(() => {
+  val x: B = null
+  C[Int](x, 0).f1.mB(1);
+  1
+}).mA()