diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue48018.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue48018.go2
new file mode 100644
index 00000000000..e6ccc6b9be7
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue48018.go2
@@ -0,0 +1,20 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type Box[A any] struct {
+	value A
+}
+
+func Nest[A /* ERROR instantiation cycle */ any](b Box[A], n int) interface{} {
+	if n == 0 {
+		return b
+	}
+	return Nest(Box[Box[A]]{b}, n-1)
+}
+
+func main() {
+	Nest(Box[int]{0}, 10)
+}
diff --git a/src/go/types/testdata/fixedbugs/issue48018.go2 b/src/go/types/testdata/fixedbugs/issue48018.go2
new file mode 100644
index 00000000000..e6ccc6b9be7
--- /dev/null
+++ b/src/go/types/testdata/fixedbugs/issue48018.go2
@@ -0,0 +1,20 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type Box[A any] struct {
+	value A
+}
+
+func Nest[A /* ERROR instantiation cycle */ any](b Box[A], n int) interface{} {
+	if n == 0 {
+		return b
+	}
+	return Nest(Box[Box[A]]{b}, n-1)
+}
+
+func main() {
+	Nest(Box[int]{0}, 10)
+}