diff --git a/windows/syscall_windows.go b/windows/syscall_windows.go
index 90358693..034b5f40 100644
--- a/windows/syscall_windows.go
+++ b/windows/syscall_windows.go
@@ -410,7 +410,11 @@ func Open(path string, mode int, perm uint32) (fd Handle, err error) {
 	default:
 		createmode = OPEN_EXISTING
 	}
-	h, e := CreateFile(pathp, access, sharemode, sa, createmode, FILE_ATTRIBUTE_NORMAL, 0)
+	var attrs uint32 = FILE_ATTRIBUTE_NORMAL
+	if perm&S_IWRITE == 0 {
+		attrs = FILE_ATTRIBUTE_READONLY
+	}
+	h, e := CreateFile(pathp, access, sharemode, sa, createmode, attrs, 0)
 	return h, e
 }