diff --git a/test/Interop/Cxx/class/constructors-diagnostics.swift b/test/Interop/Cxx/class/constructors-diagnostics.swift
index 8fa99fae7fb12..80b270c09135e 100644
--- a/test/Interop/Cxx/class/constructors-diagnostics.swift
+++ b/test/Interop/Cxx/class/constructors-diagnostics.swift
@@ -1,7 +1,5 @@
-// RUN: %target-swift-frontend -typecheck -verify -I %S/Inputs  %s -cxx-interoperability-mode=default -disable-availability-checking -verify-additional-file %S/Inputs/constructors.h -Xcc -Wno-nullability-completeness
+// RUN: %target-swift-frontend -typecheck -verify -I %S/Inputs  %s -cxx-interoperability-mode=default -disable-availability-checking -verify-additional-file %S%{fs-sep}Inputs%{fs-sep}constructors.h -Xcc -Wno-nullability-completeness
 
-// This test uses -verify-additional-file, which do not work well on Windows.
-// UNSUPPORTED: OS=windows-msvc
 // XFAIL: OS=linux-androideabi
 
 import Constructors