diff --git a/FStream.hxx.in b/FStream.hxx.in
index 5471247d7dd42606b533dc5877482fe6b55fdb3e..a9ff972a955006e7a9f2b5c163fe2637a141890b 100644
--- a/FStream.hxx.in
+++ b/FStream.hxx.in
@@ -150,6 +150,8 @@ namespace @KWSYS_NAMESPACE@
       {
 #if !defined(_MSC_VER)
         ios->rdbuf(efilebuf->buf_);
+#else
+        static_cast<void>(efilebuf);
 #endif
         if (!success) {
           ios->setstate(std::ios_base::failbit);