diff --git a/src/WNT/WNT_Window.cxx b/src/WNT/WNT_Window.cxx
index a4bfca0c03..28df3cdf10 100755
--- a/src/WNT/WNT_Window.cxx
+++ b/src/WNT/WNT_Window.cxx
@@ -462,7 +462,7 @@ void WNT_Window :: Flush () const {
 //***//
 Standard_Boolean WNT_Window :: IsMapped () const {
   if (IsVirtual()) {
-    Standard_True;
+    return Standard_True;
   }
 
   WINDOWPLACEMENT wp;