diff --git a/test/fixedbugs/issue52846.go b/test/fixedbugs/issue52846.go
new file mode 100644
index 0000000..747fc88
--- /dev/null
+++ b/test/fixedbugs/issue52846.go
@@ -0,0 +1,17 @@
+// compile
+
+// Copyright 2022 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.
+
+// Issue 52846: gofrontend crashed with alias as map key type
+
+package p
+
+type S struct {
+	F string
+}
+
+type A = S
+
+var M = map[A]int{A{""}: 0}